Yard and Garden: July 28, 2017

Yard & Garden for blog, 2017

This is the Q&A for the Yard and Garden show for July 28, 2017. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and this will be the final episode from the show for 2017. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.

Guest Host: Kevin Christiansen and Evan Alderman, Agribusiness Instructors from Southeast Community College in Beatrice

If you enjoy reading my Q&A from the show each week, take my quick survey at: http://go.unl.edu/44qr and be entered to win a free plant book or some free UNL gifts. This Survey will Close on August 18th.

1.The first caller of the day wants to know if they can still treat for bagworms that were missed with the first application?

A. If the bag is less than 1 inch in length, insecticide applications will still be effective. However, if the bags are larger than 1 inch in length, the insecticides will not work very well. Because this tree has already been sprayed this year and still has bags, I would remind everyone to ensure that they spray efficiently and according to the label, leaving areas untreated can lead to more resistance if those bagworms contacted a small concentration of the chemicals that didn’t kill them.

2. This caller called to ask me what was the best insecticide to spray for bagworms, since I left that out on the first call?

A. Tempo or Bt would be most effective. Bt is the safer alternative because it won’t harm a lot of pollinators as it just targets insects in the Lepidopteran family of insects which includes butterflies, skippers, and moths.

3. A caller has a redbud tree that blew over in a storm this spring. The roots of this tree have begun to grow some suckers. Can one of those suckers be cared for to grow into another redbud tree?

A. Yes, the suckers can be trained into a new tree. It would help the growth of the one you choose to grow if you leave the other suckers for a while as well. All of the suckers will provide energy and food to the roots, so leaving extras for a while will help. Once the main stem gets growing, you can remove the others to push the one upright.

This caller also wanted to know if he can prune his magnolia tree so he can mow under it?

A. As long as the branches are not more than half the size of the trunk and as long as you aren’t removing more than a quarter of the overall canopy the branches may be removed. The best time to prune a magnolia tree is just after it blooms in the spring, pruning now will cut off flower buds that have already developed for next spring. If the branches that would need to be removed for mowing are too large, it might be wise to change the turf to shade perennials such as carex, bleeding hearts, hostas, coral bells, jack in the pulpit, jacobs ladder, Helleborus or Lenten Rose and many other great shade plants.

4. When is the correct time to prune a burning bush?

A. Late fall after the leaves fall off would be best. It is always easier to see the branches and where problem areas are if you prune in the dormant season. Also, it will allow the plant to quickly seal up the wounds in the spring flush of growth. It is not advised to prune now because pruning woody plants after the beginning of August until when they are dormant can hurt the plant. This may cause the plant to push new growth that would be more sensitive to cool temperatures causing more dieback in the plant.

5. A caller wants to know how do you know when Butternut and Acorn squash are mature?

A. These are both winter squash varieties so the fingernail test will work just as it does with a pumpkin. When you think the winter squash is mature, push your fingernail into the rind of the fruits. If your fingernail pokes through the rind, the squash is not mature, if your fingernail does not puncture the rind, it is a mature fruit. Winter squash should have a hard rind.

6. This caller wants to know how to control windmill grass in his lawn?

A. For perennial grassy weeds such as windmill grass, there are two options for managment, either use a Glyphosate product, such as roundup, on the weed and then reseed or use a product containing Mesotrione product, such as Tenacity, on the weed and not harm the grass. The tenacity is more expensive but will not kill your grass so there will be no need to overseed.

This caller also wanted to know what would be digging up his grass?

A. This is likely due to either skunks or racoons digging the grass trying to get to grubs living in the soil. See the following NebGuides to learn how to manage these animals: Raccoons and Skunks Also, if this is due to grubs, apply a grub control next June to reduce the grub population in your lawn.

7. A caller has tomato hornworms in her garden. How can they be controlled? She also wanted to know what grubs come from and how to control them?

A. Sevin will work to control hornworms. However, the population is not usually terrible and the hornworms can be removed by hand and thrown into a bucket of soapy water for control. Grubs are the immature form of Japanese beetles, May/June Beetles, Masked Chaffer for the majority of species in Nebraska. They can be controlled in June with a grub control like the Merit products that contain Imidacloprid.

8. This caller has a 1.5 foot tall tri-colored beech that was planted in full sun this spring. About a month ago, the leaves turned brown. The caller is watering it 2-3 gallons of water every other day. What is wrong with the Beech tree?

A. Beech trees like to be in a more protected location, so this tree may be getting too much sun and too much heat. Because it is such a small tree, there is still time to replant the tree in a more protected and slightly shadier environment. Also, this small of a tree would not need this much water. When replanting it, keep it watered every other day with only about 1 gallon of water each time. After a few weeks in it’s permanent location, you can water with 1-2 gallons of water once a week and continue to back off on days between each watering as the tree grows larger. Remember, this small of a tree will not have a very large root system and it is as easy to overwater a tree as it is to underwater one.

9. How do you control moles in the lawn?

A. Moles are best controlled with a Harpoon trap that can be purchased at most hardware stores. For management tips, see this NebGuide on Moles

10. This caller has a hibiscus tree with a braided trunk that she thought would grow to zone 4, is this hibiscus going to be able to survive in Nebraska winters?

A. Unfortunately, it is highly unlikely that this is a hardy hibiscus that will survive winters in Nebraska. There is a hardy hibiscus that will survive our winters outdoors and those are suited up to zone 4, there is also a tropical hibiscus that is sold here as an indoor plant and will not survive our winter conditions outdoors. I would say that the tropical hibiscus would be the type purchased with a braided trunk. It can survive indoors during the winter months, so she can dig it up and put it into a pot to bring indoors for the winter.

2014-05-29 11.32.16

Clover in a lawn

This caller also wanted to know how to control clover?

A. Clover should be managed in the fall of the year. It will take multiple applications over multiple years to fully control clover in the lawn. Use 2,4-D or triclopyr products in the fall. It is best to apply these products around September 30th and again around the middle to the end of October.

The final question from this caller was if she should cut back her Virginia creeper plant that is turning brown?

A. Leave it alone and allow the plant to come out of the browning on its own. This is a common problem with Virginia creeper that is not terribly damaging to the plant.

11. How do you control anthracnose in tomato plants?

A. A copper fungicide can be used in a vegetable garden if necessary. However, often with home vegetable gardens it isn’t worth the time and money to spray our vegetable crops as the diseases usually only last for a short time and then fade when the temperatures change a little. However, it seems for this caller that the disease is a problem every year. For more information on controlling the disease and how to manage your vegetable gardens to avoid disease problems, visit this Nebguide on Leaf and Fruit Diseases of Tomatoes.

12. A caller has carpenter bees digging holes in her shed and wants to know how to control them?

A. Carpenter bees are a beneficial insect, except when they are burrowing into the wood framing of buildings reducing their structural integrity. They are best controlled with a dust formulation of sevin. Leave the dust in the holes a few days and then the holes can be filled in with a wood putty. For more information, see this guide from Lancaster County Extension on Carpenter Bees.

13. The final caller of the day wants to know how to control ragweed?

A. At this point, the plant is growing too strong to be killed with a herbicide. The best time to treat is in the spring before the plants have grown too large. At that time, they can be treated with 2,4-D. Now, the best control would be to dig or chop out the plants.

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Yard and Garden: July 21, 2017

Yard & Garden for blog, 2017

This is the Q&A for the Yard and Garden show for July 21, 2017. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through July 28, 2017. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.

Guest Host: Sarah Browning, Nebraska Extension Educator in Lancaster County

If you enjoy reading my Q&A from the show each week, take my quick survey at: http://go.unl.edu/44qr and be entered to win a free plant book or some free UNL gifts.

1.The first caller of the day wants to know how soon they should spray for fleas outside for an upcoming camping outing?

A. Sprays for fleas will last a couple of weeks, so it would be most beneficial to spray a week ahead of the event. Using a product containing permethrin or bifenthrin would be the best control.

2. A caller has hydrangeas that are healthy looking and green but they are not blooming, why is this?

A. This could be due to a few different factors. It could be that the plant is just slow to bloom this year due to environmental factors. Give the plant time to see if it does bloom. If the lawn surrounding the plant is highly fertilized, it may be that some of the fertilizer got into the rootzone of the hydrangea plants. Lawn fertilizers are high in Nitrogen and will cause the plant to grow nice, large, green leaves without putting any energy into producing flowers. If this is the case, make sure that you stay back away from the hydrangea next year when fertilizing the lawn. Finally, this could also be due to the plants being crowded and needing to be divided to allow the plants room to develop fully and produce flowers.

3. This caller has lilac shrubs that had not bloomed for the past few years but now this year it did finally bloom. What would cause that and how can she ensure that they bloom every year?

A. The fact that they bloomed again this year is hopeful. If lilacs are pruned at the wrong time of the year, such as in the fall or early spring, the buds will be cut off when this is done. However, the caller said she has not been pruning them at all. This could be due to the lilacs getting overgrown and having old, unproductive wood in the shrubs. It might be best to try to do a rejuvenation cutting to start all of the branches off new again. With a rejuvenation cutting, the entire plant is cut off about 6-8 inches above ground level removing all diseased, dead, and weak wood from the plant.

4. When do you divide lilac shrubs?

A. This is a woody shrub and we don’t typically divide woody shrubs due to the way that they grow. However, you can dig up the suckers that grow off the main plant and pull them out and plant them in a new location. The best time to do this replanting would be in later September when the temperatures have cooled off.

5. A caller has mum plants that have leaves that are shriveling up and turning yellow. There is only a couple of the plants on each side of her house out of a large group of mums that are not as full and not doing as well as the others. She hand-waters every day.

A. Watering daily could lead to a root rot. The roots need time to dry out between waterings. If it is a root rot, there is nothing that can be done to fix the damage already done and the plants will likely die.

6. This caller has a Rose of Sharon that is not blooming. It is planted in a location with minimal sunlight, would it be in too much shade?

A. Yes, Rose of Sharon bushes need full sunlight and will not bloom if in too much shade. This fall would be a great time to move it to a location with full sun.

7. A caller has cucumber plants with brown spots on the leaves. What would cause this and how can she avoid it killing her plant quickly like it did last year?

A. This could be a fungal disease common in cucumbers this year such as anthracnose or alternaria. Fungicides are not usually recommended in home vegetable gardens because they are typically not necessary or worth the time and money. However, if this disease quickly killed your plants last year, you could spray them with a liquid copper fungicide to keep the disease from spreading this year and killing your plants again. If they died quickly, it could also be from squash vine borer or squash bugs which can kill a plant almost overnight. Spray with a general insecticide for these insects such as sevin, eight, or bifenthrin. Wait the proper amount of days after spraying chemicals before harvesting vegetables. This time will be on the label as the PHI, or post-harvest interval.

8. This caller has a cherry tree that has a white fungus growing out of the trunk of the tree. There are no leaves on the branches in the middle of the tree and it hasn’t produced any fruit this year. What is wrong with the tree?

A. This is a shelf fungi, also called conks, appearing on the tree. Shelf fungi are the outward appearance of interior decay within the tree. When shelf fungi appear on the tree, the tree is dying and should be removed.

9. A caller has a burning bush that is growing up against the deck and some of the branches are dying in the center of the bush. Can it be pruned to remove the dead wood and to cut it back so it doesn’t block the deck? If so, when can it be pruned?

A. You can remove dead branches anytime, healthy branches should be pruned back in the late fall to late winter. The branches may be dying out due to scale insects which can get on the branches and reduce the vigor in the branches they are living on. If you find scale insect, use a systemic insecticide such as one containing imidacloprid in the early spring.

 

Dog vomit fungus

Dog Vomit Fungus

10. This caller remulched their garden this spring with a wood chip mulch. Now there is a cream colored substance on the mulch that looks like cat vomit, but they have no cats. What is this?

A. This is dog vomit fungus. It is a fungal structure much like a mushroom or puffball. It is not harmful to the plants or the mulch. It can be found on mulch because it lives on decaying organic matter such as the woodchips. It is nothing to be worried about and if you don’t like the way it looks, you can wash it off with the jet setting on your hose end sprayer.

11. A caller has a prairie area where he is trying to grow a mix of wildflowers and native grasses. However, Marestail is growing in among the desirable plants. How can he control the broadleaf weeds and not kill his desired broadleaves and grasses?

A. Once the grasses and wildflowers thicken up in the prairie, they will push out the weeds, but establishment is the hardest part. Mowing this year will help to thicken up the plants growing there and will stop seed production in the marestail which is an annual weed.

12. This caller is also starting a prairie area. He has had a 2 acre pasture of alfalfa that he now wants to change over to native grasses. What is the best method of doing this?

A. The native grasses are mostly warm season grasses, so they are best planted in the end of May to the beginning of June. Dormant seeding could be done in late November, but you need to prepare the area this fall before a dormant seeding is done. To prepare the soil, kill the existing plants this fall and clean up and aerate the soil prior to planting. You can drill the seeds in when the time comes as well.

13. A caller has an area where soil was added and leveled off. How do they overseed the area that has been overtaken by weeds at this point?

A. Spray the area with roundup to kill the weeds. You can spray now and again shortly before seeding the area. Then overseed in September with a Kentucky bluegrass or Turf-type tall fescue. Once you overseed, use a rake to get the seed to contact the soil and keep it well watered.

14. This caller has an oak tree that is not fully leafed out, the top is bare and the lower leaves are smaller. What is wrong with the tree?

A. This could be due to herbicide drift since many neighboring trees look similar. If so, there is nothing to do to fix herbicide drift once it has been done, just make sure the tree is being watered and that it is mulched in. This could also be due to the fact that the tree isn’t getting enough deep water if it is just being watered by the turf irriagation. Make sure that once every 10-14 days a slow, long irrigation is done around the tree. Trees need water down to 12-18 inches deep, lawn irrigation only waters the top 4-6 inches of the soil.

15. A caller has 2 large Norway pines. How can he get grass to grow under the trees?

A. Unfortunately, grass will not grow in heavy shade under a large tree. It would be best to try a groundcover, sedge plants, or shade perennial plants. We often continue to battle grass problems and overseeding in heavy shade, but the reason the grass won’t grow is because it is not meant to be grown in shade. In these situations it is best to find other plants that are more suited to the shade or just mulch around the tree to stop weeds from growing around the tree.

16. The last caller of the day has dwarf lilacs that are quite large. How tall are they supposed to grow?

A. Dwarf lilacs, such as the Miss Kim variety, will still grow up to 6 feet tall if left unmanaged. This is still much smaller than the full sized-lilacs which grow up to 15 feet tall. You can continually prune these lilacs in the spring after they finish blooming to keep them to a smaller size. Prune within the couple of weeks after blooming so you don’t cut any flower buds off.

Yard and Garden: July 14, 2017

Yard & Garden for blog, 2017

This is the Q&A for the Yard and Garden show for July 14, 2017. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through July 28, 2017. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.

Guest Host: Steve Karloff, District Forester from the Nebraska Forest Service

If you enjoy reading my Q&A from the show each week, take my quick survey at: http://go.unl.edu/44qr and be entered to win a free plant book or some free UNL gifts.

1.The first caller of the day has overgrown Forsythia and Yellow Dogwood plants. What can be done for pruning to reduce the unproductive plant materials and when can it be done?

A. Because these plants are overgrown, it would be most beneficial to do a rejuvenation cutting on them. A rejuvenation cutting is when you prune a shrub back to about 6-8 inches from ground level and remove the majority of the top growth. This will get rid of all the old, unproductive wood to bring in all new, younger wood that will be more productive to leaf out better throughout the entire shrub, will lead to more flowering, and will be healthier and free of insects and diseases that were problematic on the shrub. It is best to prune forsythia immediately after they flowered, but it could be done in the fall. Remember with a rejuvenation cutting that the plants will not flower for at least 2 years following the heavy pruning.

2. A caller has blue spruce trees planted in an area near a lake. Some of the spruces are 60 years old and some are 15 years old, all are dying from the bottom up. What is wrong with these trees?

A. Too much moisture can cause blue spruces to die from the bottom up, since they are planted close to a lake, they may be getting too much watering. When replacing the trees, choose a species more adapted to wet locations such as white pine, cedars, or bald cypress.

3. This caller has a green apple tree that was planted before he moved in and the apples are falling so they are ripe. The apples are not juicy and are quite porous and pithy. What is wrong with the apples?

A. After discussions on this with Paul Hay, this is just the variety of apple that is growing there. This is an apple that is used more for processing to be used in pies and sauces and not for fresh eating.

4. A caller has rabbits that are eating her hostas and lilies. What can be done to control them?

A. The only effective management for rabbits in a garden is to put up a fence that is at least 2 feet high.

5. This caller has a bur oak that was planted in the spring. The old leaves on the tree are turning brown but the new growth is green and healthy looking.

A. Be careful to not overwater a tree, especially with newly planted trees. These young trees have a small root system and do not need to be watered as heavily as an older, established tree. It is beneficial to allow the roots to dry out a little between waterings.

6. A caller has white pines that were planted too close to the driveway and now the branches hit cars when they come to park in the drive. Can the branches be trimmed back so they don’t hit cars and when can that be done?

A. Yes, these branches can be removed. Take the branch all the way back to the trunk so that they don’t regrow causing pruning to be necessary every couple of years. You can prune evergreens most any time of the year.

7. This caller has a bur oak that was planted last fall. It didn’t come out of dormancy this spring and has not grown. However, there are suckers coming up at the base of the tree, can the main tree be pruned out and the suckers allowed to grow into a new tree?

A. Yes, remove the main tree and allow one of the larger more upright suckers to grow into a new tree. However, sucker growth is not always as strong as the tree itself, so it may not perform how the tree was supposed to.

8. Can lilacs be pruned now?

A. No, it is best to prune lilacs within a couple of weeks after they are done blooming. Lilacs produce their flower buds in the summer and fall of the year before they bloom, so pruning now would cut off the flower buds for next spring. To ensure flowering for next year, wait until after it blooms next year and then prune it back at that time.

9. A caller has cypress trees that were planted 5 years ago. One of the 2 trees is in great condition with good color. However, the other one is smaller and yellow in color. The trees are only a few feet apart. What is wrong with it and can it be fixed?

A. The yellow and shorter tree may have just been a bad tree out of the gate. Sometimes our trees develop a problem in a nursery or from the seed source and never really overcome that. Also, with Bald Cypress trees, it is hard for them to overcome iron chlorosis. When these trees get iron chlorosis, they become stressed and no matter how many trunk injections, which also harm the tree, they never come out of the chlorosis. At this point, it would be best to remove and replace the bad tree.

 

Summer Patch at Christenson Field, P Hay

Photo of Summer Patch from Paul C. Hay, Nebraska Extension Educator

10. This caller is having problems with their lawn. He fertilized it in May but now it has brown patches throughout. How much water does a lawn need and how can he improve his lawn?

A. Our lawns need 1-1.5 inches of water per week on average to stay green and out of dormancy. The patches could be the lawn going dormant or they could be from a fungal disease. There are a lot of summer fungal diseases such as brown patch, summer patch, and dollar spot. They are common in the hot and humid days in late summer but as soon as that weather fades, the brown spots will turn green again. For more information on these diseases, see this TurfiNfo from UNL.

11. A caller has Bradford pears that have branches coming out 1.5 feet above the ground, should those be removed or will they move up as the tree grows? The trees also have suckers, what should be done about that?

A. If these low branches are in the way for mowing and you don’t like how low they are, they should be removed. Remember not to remove more than 1/4 of the tree in one season, so you may have to remove one this year and another next year. Those branches will always be at that level, though, so if they are in your way they need to be removed. As for suckers, cut those off at ground level and don’t treat them with anything or the spray will kill the tree as well.

12. This caller has pumpkins in his garden that are wilted during the day but at night they look fine. What is wrong with the plants?

A. If a plant looks better in the evening or in the morning but is wilted during the hot part of the day, it is heat or water stress. Make sure your plants are properly watered through this hot and humid couple of weeks of the summer.

13. A caller has tomato plants with leaves that are drying up from the bottom of the plant. The tomatoes are also rotten on one end of the fruit. What is causing these two problems?

A. Ensure that the plants are being properly watered. Vegetable gardens need 1-1.5 inches of water per week. Hand watering at the base of the plant every night is not sufficient for the root system. The plant could also be exhibiting early blight which is common right now. Remove the infected leaves, the disease will fade soon. The rotten side of the fruit is blossom end rot. This is a calcium deficiency in the plant caused by uneven watering making the calcium unavailable to the plant. Adding calcium to the soil will not help the problem, just make sure your plants are well watered and mulched in. Blossom end rot will fade soon. You can eat the good side of the fruit and dispose of the rotten end.

14. This caller has round berries on the plants of her potatoes. What are these?

A. These are the fruits of a potato plant. We typically do not see the fruits because we are growing the plants for the tubers produced underground and we harvest before the fruits appear. Remove the fruits so the plant can build the tubers.

15. A caller has roses that have uniformly round holes on the edges of the leaves and brown spots. He sprayed with rose spray and it is not working. What is wrong with the plants and how can he fix it?

A. This is likely damage caused by the leafcutter bee which is a pollinator and beneficial insect. There is no need to control this insect. Here is a great article from Jonathan Larson, Nebraska Extension Entomologist, on Leafcutter Bees.

16. How do you control puncturevine in a lawn?

A. Use a 2,4-D product in the pre-bloom stage. Management will not be achieved this time of year because the plant is large and will be difficult to kill. Also, don’t use 2,4-D products in the heat and humidity of the summer or the product may move to non-target plants causing damage.

17. How do you control moss in a pond?

A. Copper sulfate crystals can be used for control. For more information on pond management, visit the Lakes, Ponds, and Streams section of the water.unl.edu website.

18. A caller has apple trees that get insects in the fruit every year. When and what should they be spraying for that?

A. It would be best to get on a spray schedule, spraying with an orchard fruit tree spray every 10-14 days throughout the growing season. For more information visit the Local Food Production page within the food.unl.edu website for spray guides.

19. The last caller of the day has vines with milkweed type pods growing in his fenceline. What can be done to control it?

A. The plant sounds like honeyvine milkweed. At this point of the year, pull it or spray it with roundup. In the spring or fall, 2,4-D could be used, but not now due to the heat and humidity.

 

Yard and Garden: July 7, 2017

Yard & Garden for blog, 2017

This is the Q&A for the Yard and Garden show for July 7, 2017. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through July 28, 2017. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.

Guest Host: Bob Henrickson, Assistant Director of the Nebraska Statewide Arboretum

If you enjoy reading my Q&A from the show each week, take my quick survey at: http://go.unl.edu/44qr and be entered to win a free plant book or some free UNL gifts.

1.The first caller of the day has 10 lilacs growing in a lawn which are now getting a gray film on the leaves. What is causing this problem?

A. This is due to powdery mildew. This is a common problem on lilacs. Lilacs often get this disease if they are planted too closely together reducing air flow or if they are planted in heavy shade. If these plants are not growing in either of these environments, it is likely due to the wet spring we saw this year. Fortunately, this disease is not very damaging to the plants and there is no need to treat for it.

2. A caller has many American elm trees growing in his pasture that seem to suddenly be dying this year after the leaves turn brown and curl up on the branches.

A. Unfortunately, this is likely due to Dutch Elm Disease, which is still present and active in Nebraska. Many of our trees can grow for a few years and then the trees get large enough and conditions become conducive, that it shows up and kills the trees fairly quickly. The only management strategy is to remove and destroy the infected trees to reduce the spread to other trees.

chicory, Joseph M Ditomaso, Univ of CA-Davis, bugwood

Photo of Chicory from Joseph M DiTomaso, University of California-Davis, Bugwood.org

3. What are the blue flowers blooming along the roadside now and can the seed be purchased somewhere?

A. That is chicory, a non-native plant often used in roadside mixes. The seed can be found in some roadside mixes or at local seed sources.

4. A caller has a sunset maple with leaves that are curling and falling off the tree. What could be wrong with the tree?

A. This could be due to herbicide drift. Trees stressed by herbicide drift will often lose their leaves and push new growth. As long as they are producing new leaves that are not curled, the tree will likely be fine. However, many years of damage from herbicide drift can cause more stress and even possibly death.

5. This caller has voles in their yard. How can these be controlled?

A. Snap mouse traps can be placed in the runs perpendicular to the runs. These traps will catch and kill the mice. Here is a guide on vole control

6. A caller has a copper-colored beetle in her elm trees that are causing holes in the leaves. What would this be and how can they be controlled?

A. This could be a Japanese Beetle, an invasive insect from Japan. It is a green beetle with copper-colored wings. These beetles need to be controlled as they can do a lot of damage quickly. They chew on the leaves causing a skeletonization of the leaves as they leave behind the leaf veins. They can be treated with a insecticide containing imidacloprid.

7. A caller has a grass that grows in her lawn. The grass grows in a large circle about the size of a dinner plate and tends to turn brown in any kind of drought when the rest of the lawn does fine, but thrives in higher moisture content. What would this be and how can she make her lawn look more uniform?

A. This could be a cool season weedy grass species. They are often found in our lawns growing in a large circle. I would recommend spot spraying the areas of this different type of grass and then reseeding. This would be best done this fall. Be sure to spray the spot while it is still green and actively growing and use a product such as glyphosate. Overseed the areas in September.

8. This caller has hollyhocks with brown spots on the leaves. What could this be from?

A. This is likely due to hollyhock rust, a common fungus of hollyhocks. Remove the leaves as they develop the disease and destroy the leaves and plant parts removed in the fall cleanup. Fungicides can be used if necessary, such as a liquid copper fungicide.

9. A caller has peach trees that have developed some insects in the peaches making them unedible. What can be done about that?

A. There are a lot of different insects that feed on the fruits of peaches. The oriental fruit moth is one. For any fruit tree, either deal with some insect and disease damages throughout the years or keep your trees on a spray program. Spray every 10-14 days throughout the growing season with an Orchard fruit tree spray that contains two insecticides and a fungicide. Avoid spraying during full bloom. For more information, visit food.unl.edu/local-food-production

10. This caller has a sycamore that has shed some leaves and is now shedding bark. What is wrong with the tree?

A. The shedding bark could be normal. Sycamore trees have an exfoliating bark that is normal to give it the camouflage bark appearance. It may have been hit earlier this spring with anthracnose causing the leaves to drop. Anthracnose is a minor, but common, disease of sycamore trees. It is more prevalent in wet weather, such as this spring. There is no control for it, but the tree should be fine.

11. A caller has been trying to seed grass where a septic tank was and can’t get it to grow. What is wrong?

A. At this point in the year, it would be best to wait until fall to plant grass seed due to the heat, humidity, and lack of rain. However, if you have been trying in the spring and fall and can’t get it to grow, I would recommend getting a soil test done of the soil where this problem is occurring. This will help tell if the soil has other problems because of the septic tank or what was put back into the hole. It was also determined that this is an area around a large tree with a great deal of shade, if the area is too shady for grass, try a groundcover or a carex species that will grow better in more shade.

12. When is the best time to spray for bagworms?

A. Now would be a good time since the bags have emerged. Make sure you spray before the bags are 1 inch in length for best control. You can use any general insecticide for controlling bagworms such as sevin, eight, bifenthrin, tempo, or Bt can be used for a safer control method. Bt will not harm bees and other beneficial insects.

13. A caller has a Norway Spruce that is 8 feet tall. It has been drying up since this spring and looks like it is dying. The tree has been planted here for 5-6 years and is watering slowly every 2 weeks since the trees were planted. What is causing it to die?

A. This could be due to overwatering. The roots of the trees need to breathe in between waterings. If the caller is filling a moat around the trees with water every 2 weeks for this many years, it would be excessive.

14. The final caller of the day wondered if the yard could be sprayed to help with chiggers? He also wondered when the time was to use sedgehammer on the lawn?

A. Nothing can be sprayed on the lawn to entirely help with chiggers. The best defense against chiggers would be to use insect repellent that contains DEET and to wear light colored clothing. Sedgehammer is best used before June 21st or the longest day of the year to help reduce the populations of nutsedge for next year. However, it can still be used this late in the year to kill what is in the lawn this year.

Yard and Garden: June 30, 2017

Yard & Garden for blog, 2017

This is the Q&A for the Yard and Garden show for June 30, 2017. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through July 28, 2017. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.

Guest Host: Connie Fisk, Cass County Extension Educator

If you enjoy reading my Q&A from the show each week, take my quick survey at: http://go.unl.edu/44qr and be entered to win a free plant book or some free UNL gifts.

1.The first caller of the day wanted to know if he could fertilize his tomatoes, potatoes, and cucumbers with the same fertilizer?

A. Yes, the same product could be used for all three of these crops. Be careful when fertilizing to not use too much Nitrogen during the bloom period which will cause the plants to grow large but not produce any fruits. Also, too high of Nitrogen for the plants can lead them to grow large and dense which can lead to more fungal diseases.

2. A question came through email asking what would cause red spots on strawberry leaves?

A. This could be either due to leaf scorch or leaf blight. The leaf scorch will have red spots that have a red or purple center and the leaf blight will be a red spot with a gray center. For both of these diseases, you can use Captan fungicide.

strawberry leaf diseases comparisons

3. How soon can peonies be cut off?

A. Peony leaves should be left on the plant through the growing season and can be removed in the fall when the leaves turn yellow. Otherwise, this time of the year you should only remove the flower stalks. Leaving the leaves on the plant will help the plant build sugars to help it bloom early next year.

4. A caller planted Karl Forester Reed Grass in 2 locations in his landscape at the same time this spring. One location, the grasses are doing well, but in the other location, the grasses are much smaller and not growing well. The worse plants are on the east side of the house while the good grasses are on the west side of the house. What would cause them to grow so differently?

A. The east side of the house would be in more shade than those plants growing on the west side. Most of our grasses like to be grown in full sun, this difference in sunlight could cause the difference in growth. Because they are in different locations, a nutrient deficiency could be causing the few on the east side to be growing less. Add a general fertilizer to help with growth.

5. This caller is applying a fertilizer with 24% Nitrogen every 7 days to her tomato plants. Is this too high of a percentage of Nitrogen for the plants to grow well?

A. The percentage isn’t as important as how much is applied. Applying a fertilizer every 7 days is too often. For most vegetable gardens, fertilizing three times a year will be sufficient. With this high of Nitrogen in the soil the plants will not produce and may grow too large and develop diseases in the deep canopy.

6. A caller had golf ball sized hail a couple of weeks ago that hit his tomato plants. The plants are still growing and have leaves on them. Will they be ok?

A. Yes, they should be fine. Keep them mulched to help reduce competition with weeds and keep them uniformly watered as needed. Don’t fertilize the tomatoes because they are stressed from the storm damage and fertilizing a stressed plant will increase the stress.

7. This caller wondered if grass clippings will negatively affect the soil in his vegetable garden? He had been using the grass clippings for a couple of years and now his vegetable plants don’t look as healthy as before he started using grass clippings.

A. After discussions, the caller said he had been using herbicides on his lawn and using the grass clippings on his garden. Pesticides can have a long residual on the grass clippings and this can negatively affect the plants. Especially if he was using broadleaf herbicides such as 2,4-D for dandelions. Broadleaf herbicides will damage vegetable plants which are all broadleaf plants. It would be best to avoid using his grass clippings if he is to continue using herbicides on his lawn. He can use other types of mulch such as straw, woodchips, newspaper, cardboard, or grass clippings from a neighbor who isn’t using herbicides on his or her lawn.

8. A caller has hollyhocks that have copper colored, round spots on the leaves and the leaves are falling off. What is the problem and what can be done to improve the flowers?

A. This is likely due to hollyhock rust, a common fungus of hollyhocks. Remove the leaves as they develop the disease and destroy the leaves and plant parts removed in the fall cleanup. Fungicides can be used if necessary, such as a liquid copper fungicide.

9. Do weeds need to be controlled in sweet corn or will the plants grow tall enough and shade them out soon?

A. Weeds should always be removed to reduce competition and lead to better overall plant growth. You can hoe the weeds out and use mulch between rows.

10. This caller has squash plants growing in black containers that are growing in potting soil. They are not thriving, what could be the problem?

A. The pot could be getting too hot because it is black. It would be beneficial to add mulch around the container or paint it another color to keep the roots cooler inside. It also could be drought stressed. Plants grown in a container get drought stressed sooner and need to be watered more than those growing in the ground because they have more limited root space. It also might be beneficial to add a general fertilizer to help the plants grow better.

2015-04-15 11.03.06

Kabatina Tip Blight

11. A caller has flagging on cedars that is causing the tips of the branches to turn brown. What would cause this damage to 20 year old cedars?

A. This could be due to bagworms which would be very small yet. Bagworms can be sprayed with any general insecticide. It also could be due to drought stress or Kabatina tip blight. There is no fungicide control for Kabatina. The best management is to cut out the affected areas.

12. This caller has sweet corn growing in his garden. The corn is about 2 feet tall and is now tasseling and it is very light colored. What would cause this problem? He is watering his garden for 1.5-2 hours every night.

A. This is likely due to overwatering. Vegetable gardens need about 1 inch of water per week, watering every night is not necessary and that much water would cause the nutrients to leach down through the soil, which would account for the lighter green coloration. The corn will likely not produce this year since it is already tasseling.

13. A caller wondered if the wood chips being produced from all of the downed trees would be safe to use as mulch around living plants or if there would be an issue with insects in the mulch?

A. This would make a good mulch for your plants. If there was an insect in the trees being chipped, the chipping process will kill it.

14. This caller has grapes that were hit by herbicide drift this spring. The leaves were all the size of a nickel and deformed, but the plants are not pushing new growth. What should they do to help the grape plants make it through this stress? Should they fertilize the plants?

A. Unfortunately, grapes are very sensitive to herbicide drift. 2,4-D can drift about 1/2 miles and Dicamba can drift about 1 mile, so it can move from a long way and grapes will be the first to know. If these are mature plants and they are pushing new growth, they should be fine. Don’t fertilize the plants, this will add more stress to the situation. Keep them well watered to help them through.

15. A maple tree was recently hit by hail. Now the trunk and branches have wounds on them. Should anything be done to cover these wounds?

A. No, don’t apply anything to the tree or cover the wounds with anything. Allow the tree to go through it’s normal processes to seal up the damage to reduce decay further into the trees.

16. A caller has cantaloupe plants that are not growing well. They have very small leaves but they are flowering already. What can be done to help them grow better? They are growing in a garden with many other vegetable crops that are growing much better.

A. Remove the flowers that are developing on such a small plant. When plants try to push flower growth and fruiting, they reduce their growth. Removing the flowers will push the plants to try to grow more before they begin flowering.

17. This caller is growing strawberries that have been growing for a few years. They bloomed and looked healthy this year, but the strawberries produced were very small. What would cause this problem? Also, what will help stop strawberries from rotting if they ripen on the ground?

A. The plants should be thinned at the end of the year to help increase the size of the berries. They also could be dealing with an issue of poor pollination. The cool, wet weather this spring led to low pollination because the bees don’t like to fly in the rain. Poor pollination may lead to development of the fruits, but at a much lower size than normal. Poor pollination can also cause the plant to drop small fruits from the plant before they mature. Mulch the strawberry beds with straw to help keep the berries from laying on the soil and rotting as they mature.

18. A caller from the Geneva area has an ash tree. Should he be treating for Emerald Ash Borer now?

A. No, Emerald Ash Borer (EAB) has only been found in Greenwood and Omaha in Nebraska and we recommend waiting until the beetle has been found within 15 miles of your tree before beginning treatments to reduce injury to the trees and to reduce the amount of insecticides in the environment. There is no need to treat for a problem that we don’t have yet.

19. This caller has one apple tree and needs to get a second tree for pollination. What would be a good variety?

A. It is necessary to plant a second variety of apple tree to help increase pollination. Look at the local nurseries to find good choices that go with the variety you already have planted. They will have a chart to show which trees pollinate which.

20. A caller has a fungus in the lawn every year. This fungus shows up in different locations throughout the yard every year and she treats with a fungicide every year. Is there anything she can do to make it so she can stop treating every year?

A. If you see the fungus in your lawn every year, you would need to treat for it earlier in the year before the fungus appears. If the fungus is present before treatments begin, they will not stop the damage that is already present.

*A caller later on the show suggested that these spots may be due to a dog urinating in the lawn, which can cause brown spots similar to many of our summer fungal diseases. There is no way to stop the brown spots left after a dog urinates on it, you would need to walk the dog somewhere else to do his or her business.

21. The final caller of the day has tomatoes that are growing well and they are now 3.5 feet tall, however, they have no blossoms on the plant. What would cause this?

A. This would be due to high Nitrogen levels in the soil. It cannot be fixed at this time, but don’t add any additional fertilizer to the garden for a couple of years to bring the level back down.

Yard and Garden: June 23, 2017

Yard & Garden for blog, 2017

This is the Q&A for the Yard and Garden show for June 23, 2017. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through July 28, 2017. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.

Guest Hosts: Mike Onnen, Manager for the Little Blue NRD & Donnie Engelhardt, Assistant Manager for the Little Blue NRD

If you enjoy reading my Q&A from the show each week, take my quick survey at: http://go.unl.edu/44qr and be entered to win a free plant book or some free UNL gifts.

1.The first caller of the day wanted to know if it was time to spray for bagworms yet this year and what to use for bagworms?

A. Yes, the bags have emerged. There is time for a couple of weeks yet to get them sprayed, just make sure you spray before the bags are 1 inch in length for best control. You can use any general insecticide for controlling bagworms such as sevin, eight, bifenthrin, tempo, or Bt can be used for a safer control method. Bt will not harm bees and other beneficial insects.

Bagworm4

Bagworm

2. A caller has 2 large oak trees that when he parks his truck underneath it gets sticky from the aphids in the tree. What can be done to manage these?

A. The aphids are producing honeydew as an excretion and they do feed on the oak trees, but often this is not that damaging to the tree. You can spray for the aphids in the tree with a general insecticide, but if you give it a little time predatory insects will come in and kill the aphids. If you spray, you will kill the predators as well as the aphids. It is often not necessary to spray for aphids in a tree.

3. This caller has lilies that have grown too thick in her one garden bed. When can she divide these to transplant some in a new location?

A. This could be done this fall or you can wait and thin the lilies in the spring as well, either would be fine. I would advise against transplanting and dividing plants this time of year because in the heat, the plants don’t have enough roots to get to more water to keep them cool.

4. A caller has a weeping willow that has many leaves turning yellow and the tree is thinning. What would be wrong with the tree and how can it be managed?

A. This tree is likely dealing with environmental stress. There are not spots on the leaves to indicate a disease or damage that would be from insects. After viewing the photos, it is determined it could be due to improper planting as it looks too deep with no root flare. There may be stem girdling roots that would not be evident for a few years after planting.

5. How do you control ground squirrels in your yard?

A. There is a great publication on Ground Squirrels from the Internet Center for Wildlife Damage Management which shows how to set a trap for ground squirrels.

6. A caller has Iris, yucca, and prickly pear cactus that are all getting many weeds growing in and around these plants. The weeds include both grasses and broadleaf weeds. How can the weeds be controlled without injuring the desired plants?

A. The grasses can be sprayed with Grass-B-Gon or another similar grass herbicide. Unfortunately, there isn’t a selective herbicide that will kill broadleaf weeds and not kill broadleaf desired plants. For the broadleaf weeds, the best defense is to hoe the weeds out and mulch the garden in the future to hold the weeds back.

7. This caller has a plum hedge that has holes in most of the leaves throughout the hedge. The holes form initially as a brown spot and then a hole appears. What would cause this?

A. This is likely due to herbicide drift. There is no control for that, but if it is minimal it shouldn’t impact the hedge too much. However, multiple years of herbicide drift to the same plants can start to stress and in some cases kill the plants.

8. A caller has onions that have formed a soft, brown spot on the onions when they were dug recently. What would cause this?

A. This is likely a rot issue that developed from a pathogen in the soil. It is always best practice to rotate the crops. Also, ensure that you properly cure your onions before storage.

9. How can you control sandburs?

A. Crabgrass control in the spring will work for sandburs as well as foxtail and crabgrass. All of these are annual grasses.

10. A caller has tried to plant roses in the same location for a couple of years now and it seems like they grow to about 18 inches, bloom, but then die over the winter months. The are planted in a garden with rock mulch, watered with a bucket of water as needed, and were pruned off in March. Why can’t the caller get the roses to live longer than one year?

A. This sounds like mostly environmental stress to these plants. Rock mulches are hot and absorb no water, switch to a wood chip mulch to cool the roots and hold moisture. Watering should be done with a soaker hose or other type of sprinkler system. When a bucket of water is poured over the plants as needed, the water fills up the top pores of the soil surface quickly and then spread out rather than down. A slow trickle on the plants for a while each week to wet the soil down to about 6-8 inches will be more beneficial. Pruning of roses is best done in the middle of April once growth has begun further to ensure healthy wood is not also removed with the dead wood too early in the spring. Add extra mulch around the plants in the winter months, up to 4-6 inches deep in the winter months, then spread the mulch out to 2-3 inches deep during the growing season. Extra mulch in the winter will help protect the plants from inconsistent temperatures in the winter.

11. This caller wants to know when to dig up garlic? He also wants to know if bleeding hearts can be cut back now?

A. Garlic should be harvested in July after 30-50% of the leaves have died back. Harvest during dry weather and leave the bulbs on the ground to dry for a week before storing. The flower stalks of bleeding hearts can be removed, but the leaves need to be left on the plants to build sugars for next years growth and flower production.

12. How can grasshoppers be controlled if they are in the flower garden?

A. Any general insecticide will work for grasshoppers in flower gardens. Sevin, eight, tempo, bifenthrin, and others will work for flowers. When treating grasshoppers, it is also important to treat the grassy areas of roadsides and ditches where grasshoppers are often found.

13. This caller has grass growing in his asparagus patch. How can the grass be controlled?

A. Hand pull and apply a mulch to the asparagus patch. The earlier you get the mulch applied in the season, the better the control will be. Also, after harvesting is complete, the asparagus can be snapped off below ground level and Roundup or another glyphosate product can be applied as long as there is no green asparagus above the ground.

 

Grasshoppers, J. Larson

The four main pest species of grasshopper in Neb. Top row two striped grasshopper adult, red legged grasshopper adult. Bottom row differential grasshopper adult, migratory grasshopper adult.

14. How can you control grasshoppers in the vegetable garden?

A. Sevin, eight, and bifenthrin are labeled for use in the vegetable garden. Also, remember to treat for grasshoppers in tall grasses along roadsides and ditches. Follow the PHI (pre-haravest interval) to know how many days after application necessary to wait to harvest the vegetables.

15. A caller wants to know when to transplant peach trees?

A. Fall or spring are both good times to transplant any trees.

16. The final caller of the day has a pond with moss or duckweed in it making it cloudy. What can be done to clean up the water?

A. Avast SRP is labeled for Duckweed and Copper sulfate can be used for Algae.

Yard and Garden: June 16, 2017

Yard & Garden for blog, 2017

This is the Q&A for the Yard and Garden show for June 16, 2017. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through July 28, 2017. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.

Guest Host: Jim Kalisch, Insect Diagnostician from UNL Extension

If you enjoy reading my Q&A from the show each week, take my quick survey at: http://go.unl.edu/44qr and be entered to win a free plant book or some free UNL gifts.

1. The first caller of the day has a Daylily that has yellow streaks on the leaves. What is causing this? She also has Roses that are getting yellow leaves and sprayed a rose product containing both an insecticide and a fungicide. Will this work for the roses?

A. The daylilies likely have Daylily Leaf Streak, a fungal disease common on daylilies. It would be best to remove the infected leaves and destroy them from the plants as you see them and clean up the plants in the fall by cutting off all the foliage and destroying it for winter. It will also help to water from below the plants rather than using an overhead sprinkler. Also, it sounds like her daylily plants are overgrown, this fall it would help to dig and divide them to increase air space. As for the roses, they could be dealing with black spot or rose slugs. The fungicide and insecticide combined product will work to reduce the incidence of both of these problems.

2. A caller wants to know when the best time to transplant asparagus and what can be done for a cypress tree turning yellow?

A. Asparagus is best planted and transplanted in the spring. However, if this is an old patch of asparagus, it would be better to just start from new crowns. Either way, you need to wait 3 years to harvest to allow the roots to develop. Trees that turn yellow instead of their deep green color through the growing season are often lacking iron. The best management for Iron chlorosis is to use a trunk injection of iron. However, with cypress trees, it is often difficult to get them out of this condition and multiple years of trunk injections can start to stress the tree out to the point of death in some cases.

3. This caller has peonies and moonflowers in her yard and wants to know when the best time is to transplant them and how to prepare the area that was rocked to get these plants to grow well?

A. Spring will be best for establishment, but fall would be a second best option to transplant these plants. Remove the rocks that were in the new location and then till the soil, adding compost in as you till to improve the structure of the soil and add some nutrients back into the soil. When moving peonies, make sure that it is planted at the same depth in the soil, to deep and the plants will not flower. After you have planted, add some wood chip mulch around the plants to help them stay cool and hydrated. Water as needed.

4. A caller has a large blue spruce that has some browning on the needles and those needles are beginning to fall off the tree. This has started at the bottom of the tree and is moving upward through the tree. What is causing this? Can her tree be saved?

A. This could be one of two things, either a fungal disease or spidermites. After discussion, the caller stated that the needles are more of a reddish brown, which is distinct for a fungal disease called Rhizosphaera, which is common now. The trees can be sprayed with a fungicide to reduce the spread of the disease. Over time, the trees will grow new needles.

5. This caller recently planted 2 new 7-feet tall blue spruce trees. They are watering these trees at least once a week for 30 minutes and they are mulched in with straw. Now, the lower branches are droopy and wilted. Do these branches need to be removed?

A. These trees are dealing with transplant shock and need some time to build some new roots and get over the shock. Leave the branches for now and continue to water as needed.

6. A caller has a volunteer tomato plant that is about a foot tall. Can it still be transplanted now to be grown in the garden?

A. Yes, it will still be fine. The volunteer tomato will not come true from seed, so it may not be the same type of tomato as what was planted last year, but it should grow fine.

7. A caller has a bald cypress that has needles that are curling. What would cause this?

A. This sounds like drift from 2,4-D or another type of herbicide. This would happen if people are spraying these herbicides now that the temperatures have risen so high. Slight damage may be only aesthetic this year. Multiple years of damage can start to cause stress and even death to the tree.

8. This caller is growing grapes in his backyard. These grapes have black spots on the vine that the caller sees most years. The grapes then shrivel up before they can be harvested. What would cause this?

A. This sounds like a fungus. It would be best to get on a fungicide schedule with your grape plants to keep this fungus from returning every year. For more information on when and what to spray, view the Midwest Small Fruit and Grape Spray Guide

9. How do you stop zoysia grass from spreading in Tall Fescue and Kentucky Bluegrass?

A. Fall fertilization will push zoysia to grow when it is going dormant because it is a warm season grass. This fertilization will be beneficial to the cool season grasses.

10. A caller has Canna bulbs. Is it too late to plant them yet this year?

A. They can plant them to keep them alive and get sugars built up for next year, but they will likely not bloom this year. Cannas have to be dug up and stored indoors over the winter and if they are left out of the ground for 2 seasons, they may not have enough energy to grow after that. Planting the bulbs this year to get sugars for growth next year would be the best place for them to be stored.

11. This caller has patches of round grass in the lawn. How can it be controlled?

A. This is likely a perennial grassy weed such as windmill grass, orchardgrass, or quackgrass. These can be controlled with roundup and then overseeding or with a mesotrione product such as Tenacity. For more information on these weeds, view this article from Lancaster County Extension.

12. A caller has a spirea bush with dead wood in it. Can it be cut back now?

A. Yes, this isn’t the best time for a summer blooming spirea, but it will be fine. Summer blooming spirea’s should be pruned in the late winter, such as February and March for best blooms. This can be pruned back to 6-8 inches from the ground. However, if it is a 50 year old plant, as the lady stated, it may be getting old and may not return from a rejuvenation cutting as it may be dying due to old age.

13. How do you get rid of poison ivy which is growing in rose bushes?

A. It will be difficult to remove the poison ivy and not harm the roses or not get a medical reaction from the poison ivy while working to remove the posion ivy. Paint roundup on the leaves of the poison ivy now, being careful not to get the glyphosate on the roses. It may take multiple applications to kill the poison ivy entirely. Wear long pants, long-sleeved shirt, gloves, socks, and shoes when applying this to avoid getting a rash from the poison ivy.

Poison Ivy-David J Moorehead, Univ of GA, Bugwood

Photo of Poison Ivy courtesy of David J. Moorhead, University of Georgia, Bugwood.org

14. This caller has a trumpet vine that is creeping into the lawn. How can it be controlled in the lawn without damaging the parent plant?

A. Just keep mowing it off. These are likely runners from the main plant and if a pesticide is used to control the runners, it will go through the plant into the roots of the main plant.

15. This caller is curious if poison ivy oils can transfer to pine cones on the ground surrounding the poison ivy plants? She is also curious if she can trim her Iris plants back now or if she has to wait until the fall?

A. According to Clemson University, the poisonous oils can remain active for months on objects. It can be picked up on tools, clothing and the fur of pets. Anything that may carry the oil should be carefully washed. Even dead plants or roots may cause allergic reactions for a couple of years. So it is best to clean the pine cones that came in contact with the poison ivy. For more information, see this guide from Clemson

As for the Iris plants, you need to wait until fall to cut the leaves back when the leaves turn brown for the year. It gives the plant time through the summer to build up sugars to help bloom early next spring.

16. What type of tree would be recommended that is smaller but provides good shade?

 

A. Dwarf Chinkapin, Pawpaw, Redbud, Crabapple, Serviceberry

Yard and Garden: June 2, 2017

Yard & Garden for blog, 2017

This is the Q&A for the Yard and Garden show for June 2, 2017. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through July 28, 2017. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.

Guest Host: Graham Herbst, Community Forester from the Nebraska Forest Service

If you enjoy reading my Q&A from the show each week, take my quick survey at: http://go.unl.edu/44qr and be entered to win a free plant book or some free UNL gifts.

1. The first caller of the day has a Hen and Chicks plant that has grass growing in it. What can be done to remove the grass? She also has spiders in her lawn, what can she do to control them?

A. Grass-B-Gon is a product that contains the active ingredient Fluazifop. This is a grass herbicide. This product or any others containing Fluazifop can be sprayed directly over broadleaf plants with no damage to the desired plant. The spiders are not an issue outside in the lawn, in fact, they are beneficial. Spiders in the lawn are feeding on insects, many of which cause problems to our plants or bother us. Outside, spiders are beneficial. To keep them from coming indoors, home barrier sprays or tempo can be used around the foundation of the house to keep spiders and insects outside. If there is a fear of spiders, the tempo could be used where the spiders are seen.

2. A caller has a mock orange that has not bloomed for the past few years and now this year it finally is blooming some. Should it be removed? Why hasn’t it been blooming?

A. This could be due to a maturity issue. Many of our woody plants need to become established and get to a certain age before they will begin blooming. It could also be due to pruning time. Mock Orange bushes need to be pruned right after they finish blooming because they bloom on last years growth, or old wood. If they are pruned in the fall or early spring, the blooms would be cut off.

3. When is the proper time to spray for bagworms on blue spruce trees?

A.Spray when the bags are small to get the best control. It is best to spray after the bags emerge in the late spring to early summer but before the bags get longer than 1 inch in length. Mark a branch with a bag on it now and keep checking it to determine when the bags have emerged.

4. A caller has 6 table grape plants that had grapes set on. Now the grapes are dropping off and 70% are gone from the plants. What has caused these plants to loose all of the grapes?

A. This could be due to frost damage. Here is a guide from Oregon State University to describe the many factors that can hinder fruit development in grapes.

Forsythia-Richard Elzey, Flickr

Forsythia, Flickr image courtesy of Richard Elzey per CC license

5. Is it too late to prune forsythia this year?

A. It is too late to prune and not cut off any blooms for next year. Spring blooming shrubs should be pruned shortly after they finish blooming for the year. Forsythias bloomed in March this year, so it would already be starting the formation of flower blooms for next year, pruning them now would cut those buds off. If the intent is to just prune a few branches just a little, it wouldn’t impact the overall blooming of the shrub, but pruning too heavily will lead to little or no development of flowers.

6. A caller wondered where they could go to find the wrap around water bags for trees?

A. Local nurseries should carry them or there are many online locations where you can order them. These bags are beneficial to help keep the root ball moist to help get new trees established.

7. Can Grass-B-Gon be used in strawberries or phlox and will preen reduce the number of runners grown off of strawberry plants?

A. Grass-B-Gon is not labeled for use in fruit bearing tree crops and vines. So, it cannot be used in strawberry plants. It would be good to use for grasses growing in phlox and not cause any harm to the phlox. Preen stops the germination of seed to reduce weeds grown from seed in the garden, so it will not harm runners which are growing off an existing plant, not from seed. Check to make sure the preen you are using is labeled for use in strawberries, the general preen is not for use in vegetable gardens.

8. How do you transplant a wild rose?

A. First, make sure it is on your property. Then, just make sure you dig up as much of the rootball as possible and replant it right away. You could also try taking a cutting from one of the branches and dipping it into rooting hormone and placing it into a pot of gravel to get roots to grow. Once roots develop, you can plant the rose.

9. A caller wants to build a privacy border with shrubs. Would Burning bush work for this or are there other options to choose from?

A. Burning bush would be a great privacy wall with good fall color. Other shrub choices would include serviceberry or any of the viburnums. You could plant it now, just make sure the plants get plenty of water with it being this hot and the roots being minimized due to transplanting.

10. This caller has tomato plants that when they planted it they saw grubs and wireworms in the soil around it. Should they treat for this and if so, what should be used?

A. Grubs are not controlled effectively around vegetable gardens because the chemicals with the best control are not labeled for use in the vegetable garden. However, there is a fairly high threshold of grubs and wireworms in the garden before damage is too high. A few grubs or wireworms throughout an entire garden will not cause any real damage. The plants they are most problematic on would be the root crops such as potatoes.

11. This caller had 2 questions: Her asparagus has been planted in this location for 30 years and is quite spindly, why is that? Her peonies are done blooming now, can she deadhead the spent flowers?

A. The asparagus is regularly fertilized so the small spears could be due to heavy harvest or it could be getting old or too crowded. It would be time this year to stop harvesting to allow the plants to recover and make sure to stop sooner next year. Once peonies and iris plants have completed their blooming period, the flowers can be cut off and composted. Leave the leaf material on the plant to build sugars to help with the flowering next spring.

12. How do you control weeds in asparagus?

A. Hand pulling and mulch would be the best options for weed control. When the plant is done in the fall and the leafy material is all removed below the ground level, the existing weeds can be sprayed with Roundup as long as no green material from the asparagus is above ground or showing. Here is a good explanation from Backyard Farmer of why we don’t use salt on asparagus for weeds and how to effectively control weeds with Roundup.

Carpenter Bee, J. Kalisch

Carpenter Bee photo from Jim Kalisch, UNL Entomology

13. A caller has carpenter bees digging holes into the roof of a patio. What can be done about this?

A. You can plug those holes with caulk or putty or use a sevin dust in the holes. For more information on Carpenter Bees, see this article from Retired Extension Educator, Barb Ogg

14. This caller has puncture vine in the lawn. What can be used to control it?

A. 2,4-D is a good way to control it in the the spring before it blooms.

15. A caller has peonies that need to be transplanted. Can they also be divided when they are transplanted?

A. Yes, they can be cut into a few pieces when they are transplanted this fall. Just make sure that each section you cut off the plant has 3-5 eyes which are more like pink noses or knobs on the roots of the plant. Peonies are best transplanted and divided in September or October.

Yard and Garden: May 19, 2017

Yard & Garden for blog, 2017

This is the Q&A for the Yard and Garden show for May 19, 2017. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through July 28, 2017. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.

Guest Host: Jim Kalisch, Insect Diagnostician for Nebraska Extension

If you enjoy reading my Q&A from the show each week, take my quick survey at: http://go.unl.edu/44qr and be entered to win a free plant book or some free UNL gifts.

1. The first question of the day was from a gentleman wondering how to tell when to water his self-watering containers? There is no viewer or gauge to show the water level on the outside of the container.

A. Because a self-watering container is continually watering the plants in it, it can always be refilled. In this case, this container will keep your plants watered for at least a week to two so, they should be refilled before they completely dry up. I would suggest refilling the reservoir every week to 10 days.

Bagworm4

Bagworm

2. A caller has bagworms in their cedars. What is the best way to see them before they get too big to treat?

A. They haven’t hatched yet this year. Mark the branch you have a living bag on with flag tape to check the same bag every week from now until they hatch. You can also place a few bags in a container and keep it in the tree to see when they hatch in the container. Wait a couple of weeks after the initial emergence to ensure that all of the bagworms have hatched before spraying. The bags in the shade will take longer before they hatch. Once they have hatched, Bt is a good insecticide to use when they are young or you can use a product containing bifenthrin in it for longer lasting control.

3. This caller is wondering what types of problems we can expect in the garden, lawn, and trees this year due to the excess rain?

A. The rains in the spring tend to lead to more fungal diseases this time of the year, but they are not terribly harmful and many should fade out as the summer heats and dries up. Many things to watch out for would include fungal diseases in the lawns and trees. We are already seeing Peach Leaf Curl, different fungi in blue spruces, anthracnose on the leaves, and mushrooms popping up in our lawns. We will also see more problems from earthworms and fungus gnats which are mostly nuisance problems.

2015-09-22 18.45.39

Squash bugs on a zucchini

4. How do you effectively control squash bugs in the vegetable garden?

A. Squash bugs are difficult to control in our cucurbit vegetables including zucchini, squash, pumpkins, gourds, melons, and cucumbers. The best option is to kill the adults when they first emerge to manage the population before it explodes. Watch for the eggs as they develop on the underside of the leaves to destroy them before they emerge. Switch to other chemicals for management besides just using “Sevin” for control, which they are becoming resistant to. There are also lures that can be used for them which might help early in the season.

5. A caller has an Oregon Trail Maple that leafed out early this spring. Now the leaves are slightly cupped and turning yellow along the edges. What would be causing this?

A. This sounds like frost damage. If the leaves came out early, they may have been nipped by a light frost in late April. We are seeing this problem throughout many trees and shrubs this spring. The leaves may drop entirely from the tree, but the tree will then push secondary buds to produce new leaves that are not injured.

6. This caller wants to know how to propagate a lilac and a hydrangea.

A. For lilacs: A cutting can be taken from the shrub. Cut off a small, pencil-sized, branch and place it into rooting hormone than plant it into a pot of gravel that is kept moist. Once roots have formed, the plant can be transplanted into the ground. They can also be propagated through a process called layering which is where you bend a flexible branch down to the ground and plant it to allow roots to form on the branch while it is still attached to the main plant. Once roots form, cut it from the parent plant and transplant it. There is more information on this in the NebGuide: Lilacs

Hydrangeas can also be layered to produce new plants or they can be divided. It is too late to do the division this year, but early next spring you can dig up the plant and use a spade to divide the main plant and replant the pieces. Depending on the side you can get 2-4 pieces from a divided plant.

7. Is cedar-apple rust damaging to cedar trees?

A. Cedar-apple rust shows up in the spring on cedar trees as a orange, slimy, ball with horns. This is the gall that opens up with rains in the spring. Cedar-apple rust is not harmful to the cedar tree, it just uses the cedar trees as an alternate host through the winter. When these galls are seen on the cedar, that is the time to spray any susceptible apple, crabapple, pear, or hawthorne tree to avoid damage to them. For more information view this NebGuide

8. This caller has a pink peony that hasn’t bloomed well this year. There is some discoloration and fuzzy appearance to the leaves and buds. What would cause that?

A. This sounds like botrytis blight, a common fungal disease to our peonies. It is not very harmful to the plant itself, so it is not necessary to control it. In the fall, make sure you remove and destroy all of the plant material to reduce the spread to your plants next spring.

9. A caller has a Chanticleer Pear with leaves that have black spots on them and the top isn’t leafing out this spring. What would cause that?

A. This could be due to frost damage as well. Or check the tree for oozing sap along the trunk or branches. The damage could be from borers. It might also be from fireblight which would cause the leaves to turn black on some branches where the end of the branch hooks over like a shepherds crook. Fireblight is likely since this showed up in the tree last summer. If it is fireblight, prune out the infected branches and dip your pruners into a bleach water solution in between the cuts.

10. This caller has roses that had dieback from the winter. She pruned them off in early April and now it looks like the only live growth is coming from the ground. What is wrong with her roses and will they come out of it?

A. Unfortunately, these roses seem to have more dieback from the late frost we saw in April. If there is no green growth showing up on the main part of the plant, it is likely that it has died back. The roots would be shooting the new growth from the ground, but that is not going to be the same type of rose that you had there before because our roses are often grafted. The growth from the ground would be from the rootstock so it wouldn’t be the size and color of rose that was originally purchased. Unfortunately there is nothing that can be done about that. It might be time to go and choose some new rose colors for your garden.

11. A caller has a river birch tree that dropped its leaves in the summer last year. The leaves now are yellow and only the top half of the tree has leafed out this spring. They are 20 year old river birch trees. What would be causing this problem?

A. Look on the branches of the tree for signs of bronze birch borer. Some of the signs of this borer would be rippling on the branches or holes in the stem or branches. If you find the signs of bronze birch borer, you can treat it now with a borer spray or with a systemic insecticide.

12. A caller has a river birch tree that was growing in a clump and one of the trunks of the group died out. Should it be removed now?

A. Yes, any dead part of a tree should be removed as soon as it is noticed. A large part of a river birch, like this, could be hazardous if left standing after it dies. Unfortunately, when that branch is pruned off decay will likely begin but there is no way to prevent that at this point. This will likely be a large portion of the tree removed and that large of a pruning cut may not ever heal over entirely. When a branch doesn’t seal up, decay can get into the tree causing more damage. We don’t advise painting the stump with anything.

13. A question came in via email regarding a red twig dogwood. This dogwood is 4-5 years old and has never been pruned. Following the storms this week, some branches are falling over blocking a mowing path. Can those be pruned now? What should be done with it in the future?

A. Broken branches can be removed at any time. If these are just bending over, they could still be removed if necessary, but they may pop back up to their normal standing position. For future, red twig dogwoods should be pruned to the ground every 3-5 years to maintain that good red color on the twigs. They should be pruned in the late winter to early spring.

14. A lady called who has a Cranberry Bush Viburnum that has dead branches in it. Can those dead branches be pruned out now?

A. Yes, dead branches should always be removed when they are noticed. Check to ensure that these branches didn’t die due to Viburnum borers, if so, treat with a borer spray or systemic insecticide.

15. The last caller of the day has 2 different plants that have problems. A maple tree has brown specks on the leaves and they are falling off the tree. A Peony bush has leaves that are turning yellow along the edges of the leaf. What would be causing these two problems?

A. These both sound like frost damage. They will both be fine. The maple may drop all the damaged leaves and put on new growth.

Yard and Garden: May 12, 2017

Yard & Garden for blog, 2017

This is the Q&A for the Yard and Garden show for May 12, 2017. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through July 28, 2017. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.

Guest Host: Dr. Paul Read, Viticulture Specialist from UNL

1. The first caller of the day called to ask when is the best time to take cuttings from grape vines and how should it be completed?

A: To take a cutting, when you cut off the dormant growth from the previous year, you can take those branches and put them in moist sand to get them to root. After the last spring frost of the year, you can plant those rooted branches outdoors. When you do this method, you need 2-3 buds on each branch. Put at least 1 bud into the ground and have 1-2 buds out of the ground for leaf growth. At this time of the year, you can complete the layering method of propagation. For layering, just bury a few of the longer branches that are still attached to the vine. Once they root, you can cut them from the main plant and replant somewhere else.

2. A caller has a 7 year old peach tree that is dropping leaves like it is fall. What would be causing this to happen and can it be corrected?

A: This could be abiotic stress due to unfavorable environmental conditions. It could also be from peach tree borer. Look along the trunk for small borer holes or sap oozing from branches or the trunk to know if it is the borer. If borers, spray the trunk with a fruit tree insecticide spray. If it doesn’t seem to be from insects, keep the tree healthy through a good mulch ring and regular watering as needed when natural rains are infrequent.

3. This caller has 2 concord grapes that were producing well last year but were taken by the birds before they could be harvested. How can you keep these birds away?

A: Bird netting over the plants to keep the birds out is the only good, effective method of managing birds in grapes.

This caller also wanted to know what is wrong with her peach trees? She has 2 peach trees that are 9-10 years old that now have an orange sap oozing from the trunk.

A: This would be from gummosis, a fungal disease common on peach trees. There is no real cure for this disease, it is just best to prune out the small branches that are affected and cut 6-8 inches below the infected area. Dip your pruners into a bleach/water solution between cuts to prevent further spread of the disease. It could also be from peach tree borers. In that case, use an insecticide labeled for use on peaches for borers.

4. A caller has a row of cottonwoods but there is one tree in the middle that always has yellow leaves rather than green leaves. What is wrong with it and can it be corrected?

A: This is most likely due to an iron deficiency in this tree. That can be corrected by having a certified arborist come in to do a trunk injection. The granules or stakes around the tree are not very effective. Often, iron chlorosis is a sign of other problems with the tree and may be the beginning of the end for the tree. That being said, many of our trees live many years after developing an iron deficiency and some just need an iron injection every 5+ years to live a long and happy life.

Tree hole for blog

Photo of the damage occurring to the Maple tree.

5. A caller has some maples that were recently pruned and the branches had a fungus and some white powdery substance in them when the branches were removed. What is wrong with them and do they need to be removed?

A: This caller emailed me with photos of the problem so I could see for sure what is wrong with the plants and if it can be corrected or if it is a safety issue. Unfortunately, this does look like decay in the tree. Decay within the interior of the tree can be dangerous for when it may fall, the tree is not stable when it has decay. I would guess that the tree has a large limb that was removed at one time and it was too big or improperly cut and now there is a large hole leading into the tree. I would get a certified arborist out to take a look and possibly remove the tree.

6. This caller has a cedar windbreak and would like to plant crabapples. Can crabapple trees grow near a cedar tree?

A: Yes, you can plant crabapple trees near cedars, just make sure that you select a variety that is resistant to cedar-apple rust to avoid having to spray annually to avoid the damage from cedar-apple rust.

7. A caller has a blue spruce tree that is 8 feet tall and was planted 14 years ago that died over the winter months. What happened and how can it be avoided in the other trees in the row?

A: This could be due to a canker which is a fungal disease that stops the flow of water and nutrients from the canker point outward and upward through the tree. If the canker occurred on the lower part of the trunk it would cause the tree to die. There is no cure for canker and no way to prevent it. It could also be due to a root issue that could have happened when the tree was planted or in the nursery. The tree may have a root that girdled the stem killing the tree or it may have been planted to deeply. When you remove the tree, look at the root system to see if this was the problem.

8. This caller has small brown circles in the lawn all around a tree. This problem occurs every year later in the summer in the same location of the lawn. What would be causing this and can it be controlled?

A: This is most likely due to summer patch, a common lawn fungal disease that occurs in the mid-late summer. Normally, this isn’t something that is treated for because it doesn’t occur in the same location every year, but for this caller, it does. Management practices in the lawn can help, such as mowing higher and doing core aeration to reduce the thatch layer in the lawn. If necessary, fungicides labeled for summer patch can be used from now until the end of June.

Summer Patch, L. Giesler turf update

Summer Patch in Kentucky bluegrass photo by Loren Giesler, UNL Plant Pathology

9. What is a better species selection than using Bradford pear?

A: Chanticleer or Cleveland Select are better options for pear trees than a Bradford Pear. Bradford pears tend to have narrow branch arrangement that leads to more broken branches from high winds and storms. These two options are better choices because their branches are wider when arranged on the trunk.

10. A caller has a maple tree that is half green and half a much lighter green color. What would cause this and can it be corrected?

A: The soil pH is higher on one side. A disturbance on the one side could cause it to have iron deficiency on the lighter green side. Try to spray chelated iron on the lighter green side to fix the problem.

11. When is the best time to start asparagus?

A: Spring is the best time, from March to April is prime time for planting asparagus crowns. Be sure to still wait 3 years before full harvest begins.

12. The final caller of the day had 2 questions. She had botrytis on her strawberries last year and sprayed a week ago. Does she need to spray again? Also, can an Annabel Hydrangea be planted in full sun?

A: For the strawberries, apply from 5-10% bloom until flowers have finished blooming. For more information see the Midwest Small Fruit and Grape Spray Guide from Midwest Universities including UNL. Annabel Hydrangea is one that prefers partial shade. I would avoid planting it in full sun on the South or West side of a building where it would get too hot.