Yard and Garden: June 29, 2018

Y&G Blog Photo, 2018

This is the Q&A for the Yard and Garden show for June 29, 2018. 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 August 3, 2018. 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: Roch Gaussoin, Extension Specialist from UNL

1. The first caller of the day has green worms on her tomato plants. How can she get rid of them?

A. This is a tomato hornworm, a common pest in vegetable gardens. Tomato hornworms can easily be controlled by picking them off and throwing them into a bucket of soapy water or sprayed with sevin or eight.

2. A walk-in listener has buffalograss that is turning a reddish/brown color and dying in patches throughout the lawn. What is wrong with the lawn?

A. This is a disease called bipolaris leaf spot disease. The lawn should grow out of it. Adding 1 pound of Nitrogen fertilizer per 1,000 square feet would help reduce the problems with this disease. Check the lawn for chinch bugs as well, if they are also found, treat for them with insecticides.

This listener also wondered if his lawn should be mowed?

A. With buffalograss, it depends on what you desire from your lawn to determine whether you mow or not. It will be beneficial to mow the lawn at least once per year. Mowing one time per month will help thicken up the lawn overall for a better, fuller look.

3. A caller has poison oak growing up a tree. The root is next to the trunk of the tree, can it be cut off and the stump treated with Tordon?

A. Do not use Tordon in this situation. Tordon is not labeled for use in a landscape setting and it would likely kill the tree as well due to the proximity to the roots of the weed. Tordon is a mobile chemical and it can get from one root easily to another. It would be best to get the weed identified first as well, poison oak is not common here in Nebraska. It is likely that it is woodbine or poison ivy. Woodbine is not harmful to the tree. If still desired to kill the vine, use the “glove of death” which is when you wear a chemical-resistant glove and then put a cloth glove over that. Then, dip a few fingers of the gloved hand into Brush killer or Glyphosate and rub those fingers along the stem and leaves of the undesired plant to kill it.

4. This caller drilled a grass prairie this spring. Now, the grass really isn’t growing, it is mainly weeds. Should he mow it now or how can he proceed to get the grasses growing and kill off the weeds?

A. It is common for new prairies to struggle for the first 1-2 years. Mowing will reduce the weed presence and will thicken the stand of grass that is present. Be patient, it just takes time to get these native grasses really growing.

5. A caller has wild asparagus that he would like to move. When is the best time to transplant it?

A. Spring would be the best time. However, it would be more beneficial and less work to just kill off the asparagus that is growing in the wrong location and planting new crowns in the new location. There are newer, better, hardier varieties available now. Transplanting does not speed up the time to harvest over new crowns. Either way, transplanting or planting new crowns, it is recommended to wait 3 years before heavy harvest of the asparagus to ensure the roots get growing well before harvest begins.

6. This caller planted poatoes, corn, tomatoes, and onions. The leaves are now curling on some of the plants. They added horse manure this spring for compost. Did the manure contain herbicides that are now causing the damage?

A. This could be herbicide drift from nearby fields. Herbicides could be a contaminant in fresh manure, not as likely through composted manure. Be careful when using manure for food safety measures. Fresh manure should never be applied right at planting time. If using fresh manure, it should be applied in the fall to ensure any harmful bacteria breaks down before plants produce fruit that could come in to contact with the bacteria in the soil. Composted manure can be applied in the spring at planting because the composting process would break down the bacteria.

7. A caller planted 35 blue spruce trees this spring. Do they need to fertilize them? Do they need to water them?

A. Fertilizer is not necessary. Typically in Nebraska soils, the main nutrients for tree growth are found and are accessible. Water the trees about 1 inch of water per week. If we are not receiving that through rain, it needs to be given through irrigation. A soaker hose or sprinkler or even a 5 gallon bucket with a small hole drilled in the bottom would work to irrigate these trees.

8. This caller has grasshoppers in their garden and plans to spray sevin for them. Is there a better time of day to spray for grasshoppers?

A. Grasshoppers can be sprayed at anytime of day. However, it is important to spray grasshoppers while they are still small, they are easier to kill when they are younger. Also, make sure to spray the roadsides and ditches where the grasshoppers tend to congregate as well as the areas where they are damaging your plants. For more information on grasshoppers, see this Guide to Grasshopper Control in Yards and Gardens

9. How do you manage ground squirrels in the lawn?

A. Trapping is most effective. For information on 13-lined ground squirrels and how to manage them, check out this NebGuide.

10. A caller has poppies that are growing wild in her gardens. What can be done to control them?

A. Spot spray or carefully paint herbicide on the leaves of the poppy plants or use the chemical-resistant glove, cloth glove method listed in question #3. Roundup would be ok for this time of year. 2,4-D can be used in the fall, but not now with fear of volatilization to your garden plants.

This caller also asked how to move volunteer cedars that are coming up throughout her lawn? She wants to add them to her deteriorating windbreak.

A. Cedars are fairly resilient and easy to transplant. Since they¬† are still small, just dig up the small trees and get as much of the root as possible and replant them in the desired location. It would be better to wait until the fall to do this because moving them now will be hard to keep them alive in the heat of the summer. Make sure to keep the plants watered well throughout their transition period. They don’t need much water but would need it more often if they are very small because they don’t have a large root system.

2018-06-29 11.05.53

Purslane

11. Another walk-in listener has a fleshy weed that they found in their garden. What is the weed and how can it be controlled?

A. This is purslane. It is a common weed in our lawns and gardens. Purslane easily reproduces from cuttings so avoid hoeing or weed trimming through it while leaving pieces of the plant laying around on the ground throughout the garden. Purslane doesn’t like to be smothered, so a heavy mulch layer on the weed will help.

12. A caller passing through on the road wants to know how to control trees in pastures? They have been trying using 2,4-D with little success.

A. Cut off the trees and do a stump treatment with something stronger than 2,4-D such as a triclopyr product which is found in the brush killers. In a pasture, you could use tordon in this scenario to control the trees. Don’t use tordon if there are other desired broadleaf plants such as wildflowers or other trees nearby.

13. This caller has an Autumn Blaze Maple that is turning yellowish. He applied iron granules but they don’t seem to have much of an effect on the tree. What can be done?

A. Trunk injections of iron work better than granules. The trunk injections will also last for 4-6 years rather than just one year with the granules. Trunk injections of iron need to be done by a certified arborist.

14. A caller has potatoes that are growing on top but are not developing tubers. Not all varieties are affected the same. What is the problem?

A. The quick transition from cold to hot and the long-term heat this summer may have caused the plants to not produce the tubers as well. Some varieties may be better suited to deal with the heat which would explain the differences between varieties.

15. The last caller of the day wants to know if Linden would be a good replacement for Ash trees as the Emerald Ash Borer moves closer and when to transplant cherry trees?

A. Linden is a great replacement tree for ash. It would be a good idea to start the linden nearby now and remove the ash when it dies or when the linden begins to take off. Transplanting trees is best in the spring or fall. So for this year, wait until mid-September or later.

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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: 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.