Aerating a lawn…

Lawn Aeration Blog

September is the beginning of our fall lawncare season. Overseeding or reseeding lawns can be done throughout the month and at the beginning of the month we can fertilize our lawns. Toward the end of the month, fall weed control can begin, but not until our temperatures cool off more. One of the other lawn activities that may be considered is lawn aeration.

Compacted soils can inhibit the growth of your grass. When a soil is compacted, the soil particles are packed too tightly together to allow oxygen and water to pass through the soil. This can lead to shallow roots for the grass plants and in turn, can lead to less drought tolerance. Compacted soils can also lead to more thatch build up on the soil surface.

Thatch is the accumulation of dead grass stems that don’t become decomposed. In compacted soils, earthworm activity decreases, as does the activity of other decomposing organisms. The reduction in decomposing organisms leads to the build-up of thatch which can cause problems with the growth of the lawn. Lawns with a high thatch layer can begin to die because the thatch layer repels water keeping it away from the roots of the grass plants.

One of the best ways to reduce thatch and alleviate soil compaction would be to aerate the lawn. Many people interchange the terms “power raking” and “core aerating” when it comes to lawn aeration. However, these are 2 very different activities. Power raking is a more intense form of reducing the thatch layer on the lawn. It is only recommended when a thatch layer is more than ½ inch because at that point it would be necessary to renovate a lawn rather than just to core aerate.

Aeration equipment

Core Aeration Equipment, Photo from John Fech, Nebraska Extension Educator

Core aeration is the method of aerating your lawn most recommended. This is the method where a machine is driven over the lawn while it pulls out many small, core soil samples throughout the lawn. These cores are laid over the top of the lawn but help by leaving holes in the soil surface for water and air to move in and they will fill back in. Core aeration will also sever the roots of the grass plants which stimulates the plants to grow new shoots to fill in the holes.

It is best to aerate a lawn in the spring or in the fall. This time of year is best because the plants can recover before winter or summer conditions that are sometimes difficult on our plants. It is also a good time of year to aerate due to the fact that the soil has more moisture in it than in the other dry months of the year. It is not recommended to aerate a lawn when it is too dry or too wet because it is more difficult to get the tines into the soil which can damage the plants more. It is not necessary to aerate your lawn every year, or sometimes at all. If your thatch layer starts to build up, you drive on the lawn a lot causing more compaction, or if the lawn begins to look thin, aeration can be done. At most, it would only be recommended to aerate a lawn every 3-5 years.

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Where to plant a tree this fall…

Tree Siting Blog Article

It’s hard to believe that September is here already! With that, brings tree planting season. Fall is a great time to plant tree.

When planting your trees, remember to pay close attention to where you plant it to ensure that the tree can have a long, happy life in this new location. Often when we plant a tree, it is hard to visualize the full size of a tree, but remember, that small tree will grow into a much larger version. Plant the tree where it can spread its branches and live happily for many years to come.

When planting a new tree, think about what is all around the tree. Consider overhead powerlines, underground utilities, current buildings, any future construction that is planned, sidewalks, and the mature size of the tree.

When planting a tree, call the Digger’s Hotline at 811 to ensure there are no underground utilities near the location of tree planting. Remember, that the tree roots will grow, it would be best to give your tree plenty of space to grow without becoming too close to the powerlines to avoid future problems with the roots and the lines. If the utility company has to come in at any time to put in new lines this can damage the tree as well. Calling the Digger’s Hotline will also help so you don’t run into underground utility lines while you are planting. Never assume that the utility lines are deeper than you plan to dig.

Also, look at the above ground structures when you plant a new tree. Plant large trees at least 20 feet from a building to avoid damage to the building as the plant grows. Often, trees damage roofs, windows, and siding when the branches of the tree run into the building. If the tree won’t fit beside your home in the location you have picked, pick a different tree or a different planting location.

trees in powerlines

Trees growing in powerlines, Photos from John Fech, Nebraska Extension

Pay close attention to the location of power lines when planting a new tree. Plant your trees 25 feet away from overhead power lines to avoid damage to the lines or to help the crews of our electrical companies from having to send a crew out to prune the trees in the lines. This doesn’t help them to have to do this pruning all the time and it is a detriment to the overall quality of the tree to have a “V” cut through the middle of the canopy to allow for the powerlines. Smaller, understory trees should be used under powerlines to help the men and women who work for our electric company.

Once you have completed this evaluation of the landscape, you can determine the size of the tree that can be planted and from that, you can decide what tree you would like to plant. Don’t forget to look around your yard and the yards of all of your neighbors. Don’t plant a Maple if everyone else on the street has one in their front yard, pick something else. There are a lot of great trees that do very well in Nebraska environments but are not used enough such as Shagbark Hickory, Sweetgum, Pawpaw, and even a Linden.

This information came from the Nebraska Forest Service.

Butterflies…Everywhere

Butterflies blog

As a nature-loving person, with major interests in plants and bugs, I love going outside in the warmer months of the year to enjoy all the plant and insect life outdoors. One of my favorite things to view would be the butterflies. I love the unique coloration patterns and flying abilities of butterflies. This year there is a bit of an increase in population of one particular butterfly, the painted lady butterfly.

The painted lady butterfly is a pinkish-orange butterfly with black blotches on the wings. The forewings have a white-spotted, black tip. This butterfly has a wingspan of 2-2.25 inches. They are often confused with monarch butterflies but painted ladies are more pinkish in color, not striped, and are smaller than the monarch.

Painted lady, Whitney Cranshaw, CSU, Bugwood

Painted Lady Butterfly, Photo courtesy of Whitney Cranshaw, Colorado State University, Bugwood.org

Painted lady butterflies are being seen this year in quite large numbers. Many of the callers are just curious as to why there are so many butterflies on the gravel roads or if these butterflies will do any damage to their plants. Some callers are just curious why the populations seem so large this year. These are all great questions as this year, the population is quite a bit higher than other years.

Painted ladies are one of the butterflies in the nation that migrate through Nebraska every year from the south and they do not overwinter here. This year there is an abundance of painted ladies in the south. The high population has built over many years of ideal conditions for the development of painted lady butterflies in the south. The weather has been less harsh and there is an abundance of host plants there, as well, to help increase the population. This higher population coupled with the wind currents this year have led to a very high population moving through Nebraska late this summer.

Painted Lady underside, N. Stoner

Underside of a painted lady butterfly

As a butterfly, the painted lady is a pollinator insect and therefore is beneficial to have around. So, the butterflies will not damage our plants they will in fact help us. However, as a caterpillar, they do feed on some of our crops. It seems there is an abundance of host plants for them this year so it looks like we could face one to two more generations of the painted lady butterflies in Nebraska this year before the frost occurs. The butterflies we are seeing now are laying eggs on different plants, including soybeans, that will emerge into caterpillars. When that happens, those caterpillars could feed on the leaves of soybeans as well as our vegetable garden crops. However, it is NOT recommended to apply pesticides to control adult painted lady butterflies, instead just watch in your fields and gardens and treat the caterpillars if necessary.

So, the abundance of these butterflies is a good thing for our pollinated plants. Remember only a couple of years ago we had a very high population of the periodical cicada, it is just another reason that nature is so unique and so enjoyable. All insects go through periods of increase and decline in their populations, it is mostly dependent on environmental conditions as well as food and host plant availability. Enjoy the butterflies while they are here, we don’t usually get to see so many all at once.

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.

Fungi in the Landscape

Tree with Conks 3

Everyone loves a nice-looking landscape. However, sometimes unique structures appear in our landscape for seemingly no reason. Fungi can form in the lawn or on our plants. Sometimes these fungal structures look very unappealing, but that may be the only problem. However, there are times when these structures can be a sign of more problems with our plants.

Trees often develop different types of fungi on them. Some fungi develop as a green or whitish mold-like formation on the bark of the tree. This is not damaging to the tree. However, there are fungal formations on trees that can a sign of more damage to the tree. Conks or shelf fungi can form on the branches and trunks of our trees and look like shelves growing out of the tree. When you see a conk, you are seeing the outward formation of interior decay in the tree. Conks are indicators that your tree needs to be removed in the near future because the tree is decaying on the inside and therefore not as sturdy as it once was. If you have a tree with conks and would like to know if it should be removed, have a Certified Arborist inspect the tree.

Puffballs and mushrooms are commonly found in lawns. Both of these structures are fungal formations growing off of some type of decaying organic matter within the soil. They have no roots, stems, leaves, flowers, or seeds like plants do. They have no chlorophyll which is why they are not green and why they cannot produce their own food. Mushrooms found in a lawn are most likely not edible. If you are not sure about a mushroom, do NOT eat it. There are a lot of poisonous mushrooms found that can cause severe illness and even death, it is best to avoid eating if you are not 100% sure of the mushroom.

Puffballs are the large round structures that have no stalk to hold them up off the ground. When they mature or are struck by a raindrop or kicked, the puffball opens up to spread the spores to new areas. Puffballs are common in the late summer to early fall. Mushrooms are the formations found in your lawns and gardens that do have a stalk to hold them up off the ground. Mushrooms look like an umbrella and are often found where a tree is or was recently removed as they live on the roots of the tree or the decaying roots of the dead trunk. Mushrooms are found in moist environments such as during rainy spring months or in an irrigated lawn.

Dog vomit fungus

Dog Vomit Fungus on landscape mulch

We also see many types of slime molds in the landscape. Slime molds typically show up on mulch in our gardens and can take on many different appearances. One of the best named slime molds would be the dog-vomit fungus which looks just as the name implies. There are also yellow, gray, white, off-white, orange, and brick red slime molds. All slime molds are aesthetic issues and cause no problems to your plants. If they bother you, they can be sprayed off the mulch with a strong spray of water.

DSCN6327

Stinkhorn fungus in a landscape

Stinkhorns are another type of fungus we may find growing in the mulch around our flowers. Stinkhorns are small, pink stalks sticking up out of the ground with a brown, slimy cap similar to the cap on a mushroom. Stinkhorns are so named because of the unpleasant odor they can have. This is another type of fungus that causes no harm to the plants and doesn’t need to be removed.

For fungi in the landscape, there is no method of control other than hand-removal. They are either not harmful to our plants or they are just showing us the demise of the plant that is already happening.

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.

 

What’s that green beetle…

Green Beetles Blog post

All plants are wonderful. However, it is highly unlikely to find a plant that has absolutely no insect problems. This year we have been seeing a couple of unusual beetles wreaking havoc in our vegetable gardens and they can be found on our trees and shrubs as well. Japanese Beetles and Green June Beetles have been more problematic in southeastern Nebraska this year than most other years.

Japanese beetles are an invasive insect from Japan, where it is not a major pest due to the natural predators found there. This pest was first found in the United States in a New Jersey nursery in 1916 and was likely introduced in infested iris bulbs from Japan.  Since this initial introduction, Japanese beetle populations have steadily expanded westward.

Japanese beetles are problematic insects as both larvae and adults. The larvae are one of the four most common types of white grubs found in Nebraska. As a white grub, larvae feed on the roots of our grass, causing large brown dead spots in the turf that are easily lifted up like a rug from the floor. Adult Japanese beetles are 7/16 inch-long, metallic green beetles. The elytra, or wing coverings, are copper. These beetles can be distinguished from similar looking beetles by the six tufts of white hair along both sides of the abdomen. As adults, Japanese beetles feed on over 300 species of plants including trees, shrubs, fruits, vegetables, field crops, weeds, and other ornamental plant species. Some of their favorite food plants are roses, lindens, and grapes amongst others. Adult beetles feed on the foliage, flowers, and fruits of these plants. They feed on the upper surface of the leaves and cause a skeletonized pattern to the leaf where the veins of the leaf are often left behind but the rest of the leaf is chewed away. In some cases, they will consume the entire leaf. This can stress the plants, and in high populations of beetles can even kill the plant.

Green June Bug vs JB

Green June beetles are often being found this year as opposed to other years. They are very large, usually more than one-inch in length. They are dull green with some brownish coloration to the elytra and a tan border along the margins of their elytra, which are the hard wing coverings on a beetle. Green June Beetles will feed on ripe fruits and vegetables like tomatoes, corn, and grapes. They will feed on the fruits and the leaves of the plants and as an immature, they are also a white grub species.

These 2 green beetles can be controlled through multiple methods. As larvae, they are best controlled with insecticides applied to the lawn in the months of May, June, and July. There are many different options available including the most common grub control, Merit which contains imidacloprid. Pesticides can be used on the adults in plants, however, be sure to avoid use of pesticides directly on the flowers of these plants to avoid harming pollinators. Imidacloprid, sevin, eight, or other general insecticides can be used on trees and shrubs to control the beetles. In low adult populations, you can hand pick the beetles off of plants and throw them into a bucket of soapy water to kill them and not harm any pollinators.

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.

Poor Pollination

Poor Pollination, Blog post

Summer is a great time of the year. Our flowers are blooming and our gardens are growing. However, sometimes we have disappointments in the garden such as when our vegetable crops don’t produce viable fruits for us to eat. There are many reasons for that, but most of them we cannot help with. Just be patient and they will work themselves out.

Zucchini, squash, and cucumbers have been known to produce fruits that develop into only a small fruit that then falls off the plant. The reason for this is due to poor pollination. The plants in the cucurbit family have separate male and female flowers. This time of the year, only the male plants are present in the plants. To have a fully pollinated fruit that will develop to maturity, the plant needs the female flower to provide the fruit itself, but it needs to be pollinated by the male flower. A female flower is easily identified because you will see a small forming fruit behind the flower. Often times, people see the flowers on the plant and then get discouraged because a fruit doesn’t form, but both types of flowers are necessary to get fruits.

Poor pollination can also be caused due to lack of pollinators. Bees and other insects are necessary in cucurbits to ensure that the pollen is moved from the male flowers to the female flowers. Some years the weather isn’t desirable to the pollinators or we have a low number of pollinators present, which will lead to poor pollination causing the small fruits to drop off before fully developing. This year it has been quite rainy which leads to less pollination because bees don’t like to fly in the rain. Be careful when spraying for squash bugs and squash vine borers to help reduce injury to pollinating insects.

blossom end rot zucchini

Blossom End Rot on Zucchini

Blossom end rot is another reason that small fruits may not fully develop and then fall of your plants. Blossom end rot is an environmental problem that affects many of the plants in our garden including tomatoes, peppers, cucumbers, squash, zucchini, and watermelons. This is actually a calcium deficiency within our plants. Calcium is often found in adequate quantities in Nebraska soils, however, it cannot be moved throughout the soil and into the plant without even moisture. So, the problem isn’t due to lack of calcium, it is due to uneven moisture in the soils. In Nebraska, especially in the beginning stages of plant development, moisture is typically uneven due to heavy rains in between dry spells. Using calcium on your plants will not help this issue. Give the plants time and they should begin to develop normal fruits with no blossom end rot on them later in the season. Typically, we only see blossom end rot for the first couple of harvests in a season. You can still eat the fruits that develop with blossom end rot, you would just need to cut the rotten portion of the fruit off.

2015-09-22 18.45.39

Squash bugs on a Zucchini

Squash bugs and squash vine borer are coming to take over our gardens soon. This is the time of year to watch out for these problematic, common insects found affecting our cucumbers, zucchini, and the other cucurbits. Pay attention to your garden to help prevent damage. You can scout for the eggs of the squash bug. You will notice a group of tiny, copper colored eggs gathered near the intersection of the veins on the underside of the leaves. Remove and destroy the eggs as you find them to reduce the population. For squash vine borer, wrap the base of the plant in aluminum foil to stop the females from laying the eggs on your plant. You can use insecticides for both of these, just be careful to do it in the evening when the bees aren’t flying and don’t spray the flowers with insecticides to help with pollination.