Battling Weeds in the Lawn

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September is a time for the lawn. In my last article, I discussed overseeding and fertilizing the lawn, but weed control is another key to a healthy lawn. Some weeds in the lawn are often tolerated, but when the weed population begins to outweigh the turf population, management should be incorporated.

The Battle with Weeds

Plants are considered weeds because they are adaptive, aggressive and opportunistic. Weeds come into a lawn that is thin or bare. They are often found on the edges of our lawn or places where the grass doesn’t grow as well. Eventually they will work their way into the rest of our lawn. So overseeding a lawn may be the answer to reducing the weed population.

Growing turfgrass in the shade is not always possible. Even the shade mixes are not made to grow in high shade. Dense shade is not the growing condition for turfgrass and it often leads to weeds. In some cases, trees may be pruned to improve the sunlight getting to the turf, but be careful not to ruin the shape or health of a tree or shrub  just to get more sunlight to the turf. If the shade is too dense, a good alternative might be a shade tolerant groundcover or apply mulch where grass won’t grow.

Crabgrass

Crabgrass has been found in high populations this year, even in locations where crabgrass preventer was used. The University of Nebraska-Lincoln Turf department says the weather is to blame. Crabgrass germinates when soil temperatures reach 57-64 degrees at a one-inch depth, with the highest germination when soil temperatures increase to 73 degrees. Crabgrass will continue to germinate through the summer until soil temperatures reach 95 degrees. With the unusual weather we had this spring and summer, the largest amount of crabgrass germinated later than normal when the concentration of our original spring crabgrass pre-emergence herbicide was declining. This is why we saw so much more crabgrass later this summer than we usually do.

To help prevent this problem with later emerging crabgrass in the future, switch to longer lasting chemicals, such as prodiamine. You can also look to a second application of crabgrass preventer in mid-June to stop the germination of the late flush of crabgrass. There are also post-emergent herbicides to use for crabgrass, but I don’t recommend them this late in the season. Remember, crabgrass you are seeing now will die when the first frost hits. Also, it is difficult to kill a large crabgrass plant with a post-emergent herbicide.

Broadleaf Weed Control

As for when to treat for broadleaf weeds that do come into our lawns, fall is the best time to control them. In fall, perennial weeds are moving carbohydrates from the leaves into the roots for winter storage to help get them going again next spring. If you spray them in the fall, the herbicide will also be moved into the roots which makes the herbicide more effective. Also, the weather is more suitable for herbicide use than in the spring when Dicamba and 2,4-D have a potential to drift to non-target plants. Fall is also a great time to apply herbicides to kill the winter annual weeds such as Henbit either with a pre-emergent herbicide such as prodiamine (Barricade) or dithiopyr (Dimension) or with a post emergent after the henbit has germinated.

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Henbit along a sidewalk edge

The best time to apply herbicides in the fall is mid-late September and again in mid-late October. The second application helps to get better control on perennial weeds that may have been missed or were not fully killed. The second application also helps to ensure that winter annuals have germinated to help get control of those with a post-emergent herbicide. Products containing 2,4-D, carfentrazone, sulfentrazone, quinclorac, or triclopyr are all good for controlling perennial weeds in the lawn. Use caution around trees, shrubs, and landscape beds as these products can damage broadleaf plants but they will not harm our turf.

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Fall Lawncare

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Bare lawn in need of overseeding.

There are a lot of activities for us to do in the fall in our lawns to help our plants make it through winter and to improve their growth for next year. I wanted to take time to cover some of those items on your fall lawncare “to do” list.

It is now time to reseed or overseed your lawns for the fall. This is best done in the late summer or early fall, anytime between late August and the end of September. The rule of thumb is that that for each week grasses are seeded before Labor Day, maturation is speeded by two weeks. If you reseed after September 15 you could still be successful, but you increase your risk of dieback on newly emerged young seedlings in the event of an early frost. If you are a homeowner who wants to sod an area of your lawn, you can do that until they can no longer cut it from the fields.

Overseed with the same type of lawn that is already existing or a mix of Kentucky bluegrass and tall fescue. When starting a new lawn, either of these would be good choices. Avoid mixes that contain annual ryegrass, ‘Linn’ perennial ryegrass, or ‘Kenblue’ Kentucky Bluegrass. Make sure that the grass you buy contains less than 0.3 percent weed seed and No noxious weed seeds. If you prefer, you could also plant Buffalograss in your lawn, but this should be done in June and July.

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Lawn Sprinkler Photo Courtesy of Creative Commons License

When establishing new turf, use frequent, light watering practices to get the seed to germinate. Don’t let the seed dry out and don’t let it get too soggy either. As the grass grows, decrease the frequency of watering, but increase the amount of water applied. Don’t drastically change watering practices from newly seeded to established turf watering practices. Don’t apply any herbicides to newly seeded turf until after mowing 3 times on the new turf.

As for fertilizer applications, the fall fertilization is the most important fertilizer application for a lawn. However, fall fertilization recommendations have changed over the past couple of years. For a lawn, a Labor Day to mid-September application of slow release fertilizer is still recommended. Apply a granule with 50% slow release nitrogen or less. If additional nitrogen fertilizer is required later in the fall, use a product with a quick release nitrogen before mid-to late October. We used to recommend Halloween or later for the second fertilizer application and we thought two applications were necessary. New research is showing us that a second application of nitrogen fertilizer may not even be necessary, but if it is, we should move the timing up to more like Columbus Day rather than the typical Halloween time frame. This information is from Bill Kreuser, Assistant Professor and Turfgrass Extension Specialist from the University of Nebraska-Lincoln.

Mowing is always on our minds this time of year as well. Continue mowing through the fall as long as the grass is growing and needs to be mowed. You don’t want to leave long grass blades through the winter as this can smother the grass and lead to snow mold. Also, be sure to rake up leaves that fall on the lawn through the fall as this can also lead to snow mold. You can mow over the leaves with a mulching blade rather than rake them if you prefer.

 

Yard and Garden: August 3, 2018

Y&G Blog Photo, 2018

This is the Q&A for the Yard and Garden show for August 3, 2018. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am this was the final episode for 2018. It can be found again next spring on kutt995.com for online listening. If you enjoy reading my Q&A from the show each week, take my quick survey at: go.unl.edu/yardandgarden18 and be entered to win a free tree diagnostic book.

Guest Hosts: Kevin Christiansen, Horticulture Instructor at SCC Beatrice & Evan Alderman, Turfgrass Management and Horticulture Instructor at SCC Beatrice

1. The first caller of the day has a windbreak that has elms growing in it. How can he kill the elms and not harm the windbreak trees?

A. In this situation you need to use a herbicide that will kill the elms but will not be translocated through the roots into the surrounding windbreak trees. Tordon should NOT be used in this location. A good option would be either glyphosate, Roundup, or a 2,4-D product. Use these 2 products as a stump treatment on the tree just after cutting the tree off.

2. A caller has cucumbers that are blooming but are not producing any fruit yet. Why are the cucumber not producing? This caller also wondered how to control puncturevine?

A. The cucumbers could be due to no female flowers, if all the flowers are male, they will not produce any fruits. Sometimes our plants start with just male flowers and the females will come in later. It could also be due to low pollinators around the plants. If not many bees or beetles or other insects are found around the plants, they cannot be pollinated and may need to be hand pollinated. Hand pollination can be done by running a cotton swab through all of the blooms, this would move pollen from male flowers to female flowers. Puncturevine can be controlled with a 2,4-D product in the fall. Apply the 2,4-D in mid-September and in mid-October.

3. When should you transplant surprise lilies?

A. Surprise lillies can be transplanted or divided just after the flower dies back in the fall.

4. This caller has foxtail in the vegetable garden. Can anything be sprayed in the garden to control the foxtail?

A. There is nothing that can be sprayed over a garden to control foxtail and not harm the garden plants. The best option would be to use preen in the spring and summer to stop the germination of annual weeds such as foxtail. Be sure to use the preen that is labeled for use in a vegetable garden and wait until after all seeds planted have germinated. Mulch would help suppress the weeds in the garden as well. Grass clippings, straw, or other organic mulches will help keep the weeds down to help your vegetable plants grow better.

5. A caller was looking for assistance choosing fruit trees for his acreage. He also has rust on his fruit trees and wants to know how to manage it.

A. There is a great NebGuide on Fruit Tree Cultivars for Nebraska. For rust, this is not the correct time to treat for it. You can spray your trees in the spring with a liquid copper fungicide. For more on care and pest control of your fruit trees, visit: https://food.unl.edu/local-food-production

6. This caller has a windbreak of Red Cedars that are losing limbs. The trees are 100 years old and 30 feet tall. What is wrong with them?

A. This could be due to old age. It may be a good idea to start a new row of trees on the inside of the old row.

7. A caller has nutsedge in his lawn. What can he spray it with and can he still spray it?

A. Sedgehammer is the best control for nutsedge. It can still be sprayed now, however more control will be achieved if applied in the beginning of June, prior to the first day of summer. If sprayed before June 21st, nutlet production will be reduced, thereby reducing the population for the following year.

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Tree planting in the fall

8. This caller wants to know when the best time is to transplant an oak tree?

A. Fall or Spring are both good times to transplant a tree.

9. How do you control cattails and water lilies in a pond?

A. Rodeo is the glyphosate product that is labeled for use in water and it can be used on both of these weeds.

10. How can you control crabgrass and nutsedge in a lawn

A. Quinclorac can be used now for both of these weeds. Or use a pre-emergent herbicide in the spring and again in June for the crabgrass and sedgehammer for the nutsedge in June. Tenacity is another product that should work on both of these weeds.

11. A caller wants to know why we should worry about getting rid of cattails and water lilies in a pond?

A. Weeds in a pond can strangle the waterways or destroy habitat for fish. Some plant life along the edge of the pond can be beneficial, but too much can be a detriment.

12. This caller has lilies with caterpillars in the stem. What are those and how can they be destroyed?

A. This is likely a cutworm. Sevin or eight or Bt applied at the base of the plant can help kill these pests before they damage your plants.

13. When is the proper time to apply a winter fertilizer on a lawn?

A. Fall fertilizer can be applied in late August to mid September and the winter fertilizer can be applied in the middle to late October. It is no longer recommended to apply the winter fertilizer in November as previously recommended.

14. A walk-in listener has a weed they need identified and they need to know how to control it?

A. This is a weed called nimblewill. It is a warm-season grassy weed. It can be treated either with Roundup or Tenacity. If you use Roundup and reseed, apply the roundup now, while the nimblewill is still green and then overseed in a couple of weeks through the end of September.

15. This caller has spaghetti squash that was looking great and then one day it just died. What caused it to die and how can the other plants be protected?

A. This is likely due to squash vine borer. You can use sevin or eight to protect your plants from the squash vine borer. Be sure to apply it at the base of the plant where the plant comes out of the ground. These chemicals will need to be reapplied every 10-14 days throughout the growing season to protect the plants. Otherwise, you can wrap the base of the plant in aluminum foil to prevent the borer from getting into the plant.

16. A caller has watermelons with yellowing leaves. This has happened to his plants 3 years in a row now, he does rotate the crops in the garden. This damage starts at the base of the plants and will eventually kill the whole vine. He has mulch on the garden and waters slowly with a hose for 2 hours at a time. What is causing this problem? Also, when do you transplant iris?

A. This looks to be alternaria leaf spot. He is doing many things to prevent this disease already with mulch and his watering practices. It might be beneficial to try a liquid copper fungicide this year and next year as soon as the symptoms begin. Iris can be transplanted in the fall, September or October would be best.

17. A walk-in listener has a tree they want identified and they want to know why it keeps suckering and what they can do with the suckers?

A. This is a silver maple tree, they are prone to suckering. Suckers should be just cut off as they grow to reduce the amount of energy they take from the main tree. Do not treat the suckers with anything as that could injure or kill the main tree because the suckers are growing off the main tree roots.

18. This caller wants to know why their pepper plants are not growing well?

A.The peppers are planted too closely to a black walnut tree and will not grow well in that location. Black walnut trees produce juglone, which is basically a naturally produced weed killer. Certain plants are more sensitive to juglone, tomatoes and peppers are quite sensitive. The garden should be moved to at least 50 feet from the black walnut of the plants should be grown in a container or raised bed to avoid problems with the juglone.

19. The final caller of the year has hostas planted in a rock garden and they are not growing, they are still small like they were just planted there.

A. The rock garden may be too hot for the hostas and the rocks do not provide any nutrients back to the plants. It might be best to switch to a wood chip mulch to help reduce the heat and add some nutrients and organic matter to the soil.

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Bindweed

This caller also wanted to know what to do to kill the bindweed growing in her Iris beds?

A. Among other plants it is best to 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 Glyphosate and rub those fingers along the stem and leaves of the bindweed to kill it. Basically, the idea is to keep it from flowering and producing more seed, hand pulling will help keep new seed from being deposited into the garden which can be viable for up to 60 years.

Yard and Garden: July 27, 2018

Y&G Blog Photo, 2018

This is the Q&A for the Yard and Garden show for July 27, 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: Steve Karloff, District Forester for the Nebraska Forest Service

1. The first caller of the day has tomatoes that are rotten on the bottom. What is wrong with them and what can be done?

A. This is blossom end rot, it is where the blossom end (or the end of the tomato farthest from the plant) rots. It is due to a calcium deficiency due to uneven watering. The calcium is in the soil, but uneven watering makes it unavailable to the plant. Mulch will help keep the soil at a uniform moisture level to help protect plants from this disorder. Blossom end rot is a short-term problem in our vegetable crops. It tends to only affect the plant for a the first couple of harvests of the year and then the plant grows out of it. You can cut the black end off of the fruit and eat the rest.

2. When is the best time to prune lilacs? This caller has one that is a large, overgrown lilac that needs to be pruned.

A. The best time to prune a lilac is in the spring within a couple of weeks after blooming has concluded for the season. If it is a very large, old plant, it can be pruned all the way back to 6-8 inches above ground in a rejuvenation pruning. Rejuvenation pruning does just what the name says, rejuvenates an old, less productive plant to provide better foliage, flowering, and overall health. Rejuvenation pruning can be done in the fall. The lilac will not flower for a couple of years following this type of pruning, but it will bloom again.

3. This caller planted a large amount of black walnuts last year. Now the weeds are taking over the trees. How can the weeds be controlled without injuring the trees?

A. Simazine is a pre-emergent herbicide that can be used around walnut trees that have been established for at least 12 months. This is a pre-emergent herbicide so it won’t clean up the weeds that are growing now. For those weeds, it would be best to do hand weeding with a hoe to not injure the roots of the trees and then apply the Simazine this fall. Be sure to follow the label on how to apply and how to mix the chemical.

4. A caller has a redbud tree that is 15 feet tall and is now developing a split where multiple leaders have forked up from the main trunk. What can be done to prevent further splitting? Can one side of the tree be removed to fix the split?

A. The best option would be to remove one side of the tree or bolt it together. However, removal of one side of the split would result in removing too much of the canopy of the tree. Either side of the split would be pruning off a branch that is more than 1/2 the size of the trunk, which is not recommended. Because this is a redbud, and it shouldn’t get much larger than it is now, bolting the 2 sides together may be an effective management option for this tree. A bolt in a larger tree in this situation would likely not be very effective once the tree grew to full size, but with a smaller tree it would be more beneficial. The best thing for all trees is to remember to prune them while they are young to prevent these situations from occurring, but that is not always an option and it is hard to remember to do this.

5. This caller has some pin oaks that were planted 2 years ago and are 2-4 feet tall. The new leaves are being eaten off the tree. The leaf veins are still on the tree, but most of the rest of the leaf is gone. He has looked and can’t seem to find any caterpillars. What would cause this and how can it be managed?

A. This is likely due to scarlet oak sawfly. It is a common pest of oak trees that has 2 generations per season here and we are just finishing up the second generation in the immature stage. Because the damage is mostly finished for the year and because the tree faced minimal damage, there is no need to spray for this sawfly.

6. A caller had a daylily plant that she transplanted a month ago and it died. What caused that? What time of year is best to transplant peonies?

A. June and July are not the time of year to transplant anything, it is too hot, humid and dry to move a plant. I would assume the daylily died due to heat stress. When a plant is moved, it takes time to build the roots back up to where they can survive such heat and low water that we see in the summer months. It is best to wait to tranplant anything until the spring or fall of the year so they can become established in cooler temperatures than in the heat. Peonies can be transplanted this fall, in September. Remember to keep the plant at the same depth in the soil or it will not bloom.

7. The last caller of the day sent some photos of his red maple trees wanting to know if they will survive?

A. The trees were planted last year and now one of them has no leaves on the top 1/2 of the canopy of the tree. The other has very wilted leaves. When the top half of a tree dies like this, it is likely due to a watering or root issue. I would say this tree should be replaced, it will not grow out of it. The roots could have been injured in the nursery or at the garden center he purchased the trees at. The roots also could have been injured when they were planted. The tree that is still fully leafed out may have a chance to live, give it TLC and it might pull through. Water the tree with 1 inch of water per week and add a mulch ring around the tree that is 2-3 inches deep. The leaves could be wilted due to heat and drought stress and the watering and mulch will help it to survive.

Yard and Garden: July 20, 2018

Y&G Blog Photo, 2018

This is the Q&A for the Yard and Garden show for July 20, 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: John Porter, Urban Agriculture Program Coordinator for UNL Extension and Nebraska College of Technical Agriculture (NCTA)

1. The first caller of the day has holes in her yard that are 1-1.5 inches across. Is this ground squirrels? How can she control them?

A. This does sound like damage from ground squirrels. Ground squirrels can be controlled through trapping, baits, or toxicants. For more information on controlling ground squirrels, visit this guide from UNL Wildlife.

2. This caller has Virginia creeper that is having some issues. The first set of leaves have rust spots and holes on them and the new leaves are showing up but the buds are not opening. This plant is growing in part sun. What is wrong with it?

A. This could be a fungus on the leaves of the Virginia creeper that is leaving a shot-hole appearance behind when the dead areas of the fungus get dry and brittle and fall out of the leaf. If it is a fungus a copper fungicide or chlorothalonil to control it. There could also be some heat stress occurring causing the new leaves to not open up. There is also a possibility that herbicide drift has also occurred that has caused the leaves to not open up.

Harlequin Bug, Alton N Sparks, Jr, Univ of GA, Bugwood

Harlequin Bug photo from Alton N. Sparks, Jr., University of Georgia, Bugwood.org

3. A caller has horseradish with bugs on it that are beetle-like and are black with orange spots on them. What are these bugs and how can they be controlled?

A. These are most likely Harlequin bugs. They can be found on horseradish and they can do a great deal of damage. Harlequin bugs are a true bug, like a stink bug, They suck the juices out of the leaves of our plants leaving them wilted and discolored. They can be managed with the pesticide sevin.

4. A walk-in listener works with the football field in town. They have brown spots throughout the field and have found some caterpillars and a large amount of tiny, worm-like creatures. What are these? What is causing the brown spots? How can these problems be solved?

A. These caterpillars are sod webworm. They are a pest of turf. These caterpillars can cause brown spots in the lawn. Triazicide is labeled for sod webworms and would give pretty quick knockdown. The worm-like creatures found on the lawn could be nematodes or they could be fungus gnat larvae. Fungus gnat larvae rarely cause serious damage outside.

5. This caller is having difficulty with tomatoes ripening. What is the problem?

A. The hot weather is causing poor pollination. The pigments responsible for the red color in our tomatoes are not produced when the temperatures exceed 85 degrees. So, when we see long stretches of very hot weather, our tomatoes will not ripen. Be patient, they will ripen eventually when the very hot temperatures recede.

6. A caller is having problems with weeds in his asparagus. Will preen work now to control the weeds? Also, does he need to water his asparagus in the winter months because his asparagus isn’t growing very well.

A. Preen should be applied in the spring to control annual weeds, it will not do anything to control weeds that are already growing in your asparagus. At this point, hand pulling and applying a layer of mulch would be the best option for managing the weeds in the asparagus. When the asparagus is cut back this fall or before it begins to grow in the spring, glyphosate (Roundup) can be used to control the weeds. The glyphosate product can be used directly over the asparagus patch as long as no green from the asparagus is growing above the ground. Then, apply a layer of preen (make sure it is labeled for use in the asparagus) and add the layer of mulch.

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Bagworm

7. The last caller of the day has bagworms in their windbreak. The bags are 1-1.5 inches in length. What should they do about these?

A. Pesticide sprays for bagworms are not going to be as effective now. It is better to control the bagworms from when they hatch until they are up to 1 inch in length. Spraying a chemical now would kill some, but the rate would not be nearly as effective as before. It might be better to just handpick the ones you can reach and watch for it next year to be able to spray sooner in the season when it is more effective.

Problems in our Gardens

Vegetable garden 1

Growing my own produce in my backyard is one of my favorite things of summer! Vegetable gardens are great exercise, give you an excuse to eat healthier, and are very enjoyable but they can be a lot of work as well. There are always problems in our vegetable gardens, usually they are temporary or easily fixed.

Production Issues

The weather this year has not been favorable to our plants. We have been facing aborting flowers of our plants due to heat and low pollination. Now, even though our plants are producing, the tomatoes are not ripening up. The hot weather contributes to this as well. When temperatures are consistently as hot as they have been lately, tomatoes may develop but they don’t turn red. According to Purdue University, the pigments responsible for the red color in our tomatoes are not produced when the temperatures exceed 85 degrees. So, when we see long stretches of very hot weather, our tomatoes will not ripen. Be patient, they will ripen eventually when the very hot temperatures recede.

Blossom end rot is also starting to show up in our gardens. Blossom end rot is when the blossom end (the end not attached to the plant) begins to rot. This is due to uneven watering, which is seen quite often in the early part of the growing season where we see stretches of drought surrounded by 2-3 inch rains. Again, this should fade through the season as the plants grow through it. You can still eat the other end of the tomato and discard the rotted end or give your plants time, the next harvest should be better.

Cracks may also start to appear in our tomatoes due to the weather. With uneven watering comes cracks in our developing fruits. Our fruits can grow rapidly due to rapid intake of water which can build up pressure in developing tomatoes. Cracks typically appear on the top of the tomato, often in rings, and are not harmful to us if we eat them. Check for insects that may have gotten into the cracks of our fruits before eating.

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Grass clippings are applied as mulch around zucchini and cucumbers

Using Mulch

Mulch is a great way to combat these issues. Many of our problems in our gardens stem from uneven watering or plants that got too hot and dry to deal with the stresses of the environment. Mulch can keep moisture around the plants and keep the roots cooler to help with these issues as well as reduce competition from weeds. Grass clippings make a great mulch. If the grass has been treated with any herbicides this season, look at the label to know if or when it can be used as a mulch. Grass clippings break down quickly so they should be reapplied often. Straw is also a great mulch for the garden and it wouldn’t need to be reapplied as often. These types of mulch can then be tilled into your garden at the end of the season or before next season to add nutrients back into your soil.

squash vine borer damagePests

Squash bugs and squash vine borer are seen in our gardens every year. Squash bugs cause yellow speckling on the leaves and feeding damage on the fruits. You may also see rusty colored eggs on the underside of the leaves that can be removed and destroyed. Squash Vine Borer causes rapid death and wilting of the plants. These pests feed on plants in the cucurbit family, which includes zucchini, squash, cantaloupe, watermelon, cucumbers, pumpkins, gourds, etc. Squash vine borer can be controlled by wrapping the stem of your plants with aluminum foil to stop the females from laying their eggs on your plants. Other controls include Carbaryl (Sevin), Permethrin (Eight), or bifenthrin (Bifen). This will need to be reapplied often through the growing season. It is best to switch between at least two of these products to avoid resistance from developing.  Always follow the label recommended rates and follow the pre-harvest interval listed on the label when harvesting fruits and vegetables after using chemicals.  Spray the undersides of the leaves and the base of the plant thoroughly.  All sprays should be done later in the evening to avoid damage to bees and other pollinators.

Yard and Garden: July 13, 2018

Y&G Blog Photo, 2018

This is the Q&A for the Yard and Garden show for July 13, 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: Bob Henrickson, Horticulture Program Coordinator for the Nebraska Statewide Arboretum

1. The first caller of the day has a bug zapper that was recently emptied. The zapper contained quite a few of these small, brown, bean seed-shaped insects. What would this insect be?

A. Based on this description, it could be June bugs. These smaller, copper colored beetles are common right now and they are attracted to lights at night. If you have a lot of June bugs, you may want to pay close attention to your lawn and any possible brown spots in it. The immature stage of June bugs are white grubs that feed on the roots of our turf.

2. A caller has a climbing rose that is 8-10 years old and it was recently cut down to about 15 inches tall, against the homeowners wishes. Will this plant survive?

A. This isn’t the ideal time to prune a rose, but it should be fine since prior to the pruning it was in very good condition. Make sure to keep the rose well-watered and keep a layer of mulch around it to keep it healthy during this time of heat as the rose will try to push new growth. Water it with 1 inch of water per week unless natural rainfall provides that. Keep the mulch 2-3 inches deep.

3. This caller has an elm tree that has a hole in the base of the tree that goes in about 1 foot deep. Will the tree be ok?

A. A picture was requested for this tree to determine the severity of the hole. This could be due to many different factors including a crown rot, root rot, or other type of root damage. The hole is not very large, but because it is a foot deep, there is a concern for the strength and stability of the tree. Keep an eye on the hole, if it gets larger or if the canopy starts to thin, it would be a concern that would need to be removed before it falls on something.

blossom end rot, tomato, David B. Langston, Univ of GA, Bugwood

Blossom End Rot on Tomatoes, Photo from David B. Langston, University of Georgia, Bugwood.org

4. A caller has a black spot on the bottom of his tomatoes. What is causing this and can it be cured?

A. This is blossom end rot, it is where the blossom end (or the end of the tomato farthest from the plant) rots. It is due to a calcium deficiency due to uneven watering. The calcium is in the soil, but uneven watering makes it unavailable to the plant. Mulch will help keep the soil at a uniform moisture level to help protect plants from this disorder. Blossom end rot is a short-term problem in our vegetable crops. It tends to only affect the plant for a the first couple of harvests of the year and then the plant grows out of it. You can cut the black end off of the fruit and eat the rest.

5. This caller has a tropical hibiscus that she has moved outdoors for the summer. This hibiscus was looking fine but now some of the leaves are turning yellow. She waters every other day and it is on a wood patio on the south side of her home. What is causing this yellow color?

A. This could be heat stress due to the fact that this plant is in a location on the south side that gets very hot. She also should test the soil with her finger prior to watering to be sure to not overwater. If the soil is dry, water. If the soil is still wet, wait longer before watering again. This could also be due to spidermites. You can test for spidermites by placing a sheet of white paper below a few of the leaves and tapping on the leaves. If a few pieces of pepper seem to be moving on the paper, that is spidermites. If it is spidermites, the plant can be sprayed with a strong spray of water to knock the mites off and kill them or you can use Eight (permethrin) on it.

6. A walk-in listener brought in a plant that he needs identified. It is growing like a shrub with orange and red berries and it is spreading rapidly. What is it?

A. This is a plant called Tatarian Honeysuckle, it is a weedy species. It is spread rapidly by birds. Cut it off now before it becomes more established. Treat the stumps with Roundup or Brush Killer.

Sandbur, Rebekah D. Wallace, Univ of GA, Bugwood

Sandbur, Photo from Rebekah D. Wallace, University of Georgia, Bugwood.org

7. Does 2,4-D work on sandburs?

A. No, sandburs are a summer annual grass like crabgrass. Using a pre-emergent herbicide in the spring for crabgrass will control sandburs as well. If you didn’t use a pre-emergent in the spring, Roundup would work on sandburs but 2,4-D will not be very effective.

8. This caller has chokeberries that are about 4-5 years old and starting to set on. How do you know know when they are mature for harvesting?

A. At this point of the year, there should be clusters of small green fruits setting on the shrubs. The berries will turn dark purple in color when they are mature. There is a large harvesting window for chokeberries and the birds don’t come to this plant until after clearing the berries off of more preferred plant species.

9. A caller has sunflowers that were planted from seed and they have been coming back. The plants are similar to other sunflower plants seen around town but the flowers are much smaller than neighbors’ flowers. Are there different types of sunflowers?

A. There are a lot of different varieties that would influence the size of the flowers. Sunflowers are annual plants, so if they are coming back each year, they are coming back from seed. Sunflowers may not be true to seed so the type of flower may have changed over time or from year to year.

puncturevine seeds, Steve Hurst, USDA NRCS PLANTS Database, Bugwood

Puncturevine seeds, Photo from Steve Hurst, USDA NRCS PLANTS Database, Bugwood.org

10. This caller wondered if the caller from question #7 may have been referring to puncturevine as they are commonly confused?

A. These plants do commonly get confused because they both produce a seedhead that sticks to your clothes or shoes. They are both annual plants as well. However, puncturevine is a broadleaf while the sandburs are grasses. A 2,4-D product will work to control puncturevine, but the pre-bloom stage is going to be most effective.

11. The final call of the day has bugs flying around their tomato plants and eating the tops of the fruits. What is that?

A. After seeing a photo of the damage to the fruits, it was determined that this is due to the tomato fruitworm. Tomato fruitworms can be controlled with sevin or eight. If there are insects flying around the plants as well, that is likely something different such as Japanese beetles. It is possible, and likely, that this caller has multiple insect issues. However, both of these pests will be controlled if he sprays for one, they are both affected by the same pesticides.

Yard and Garden: July 6, 2018

Y&G Blog Photo, 2018

This is the Q&A for the Yard and Garden show for July 6, 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: Dennis Ferraro, Wildlife Specialist from UNL

1. The first caller of the day wants to know if borers from ash trees can get into his walnut trees?

A. Some native borers can be a problem in both ash and walnut trees, such as the redheaded ash borer which is a common borer in many of our trees in Nebraska. When the Emerald Ash Borer gets to southeast Nebraska, it will not be able to. EAB is a pest in Ash trees only.

He also wanted to know how to move woodchucks and not kill them?

A. Live trapping will work for woodchucks. Use cucumbers or corn to bait them and wire the trap open for a few days before actually activating the trap because woodchucks are very cautious and will not be trapped the first time or 2 into the trap. The woodchuck can then be relocated to within 100 yards of the trapped location. State regulations prohibit relocation farther than 100 yards. It would also work to change their nesting location. This woodchuck is found under a building, so if you can chase it out during the day then pack the hole tightly with road gravel will prevent them from coming back. For more information, visit the UNL Wildlife website on Woodchucks.

2. A caller has heard that bull snakes will keep rattle snakes away. Is this true?

A. These 2 types of snakes do get along but bull snakes are more aggressive hunters and can out-compete rattle snakes. Because of this, rattle snakes usually relocate to find food.

3. This caller has tomatoes with bumps along the stem of the plant. What is wrong with the plant?

A. There is nothing wrong with tomatoes that develop bumps along the stem. These are aerial roots which are common.

4. A caller has a white powdery substance on her peony plants. What causes this and how can it be controlled?

A. This is most likely powdery mildew on the peony plants. It is a common disease we see this time of the year. There is no need to treat the plants for it right now. The best control for powdery mildew is to cut off the plant in the fall when it dies back and destroy the infested plant material so the disease cannot overwinter. It will not kill the plants.

5. This caller has tomato plants with leaves that are turning yellow and the plant is not producing tomatoes, any flowers produced fall off. What is wrong with his tomato plant?

A. This is likely due to environmental stress or possibly Septoria leaf spot. Make sure that the plants are watered 1 inch of water per week, they have mulch, and they are being watered from below. If desired, a fungicide can be applied. For more information view this NebGuide on Leaf and Fruit Diseases of Tomatoes. The poor pollination is common this year due to the heat. Give the plants some time and they should start to produce.

6. A caller has a sycamore tree that is shedding bark. What is wrong with the tree?

A. It is normal for sycamore trees to lose some bark. It is a tree that has a camouflage bark appearance due to the fact that it sheds some bark. Nothing to worry about or to do to fix it.

7. This caller is growing petunias in a hanging basket and the leaves are turning yellow. What is wrong with them?

A. This could be due to environmental stress. Make sure they are kept watered and placed in a location where they get full sun. It might also be from spidermites, look closely at the plant to see if there is any very fine webbing. If so, use a strong spray of water to knock the spidermites off and kill them.

8. A caller has bindweed in his garden and in his lawn. What can be done to control it?

A. In the garden, 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 Glyphosate and rub those fingers along the stem and leaves of the bindweed to kill it. Basically, the idea is to keep it from flowering and producing more seed, hand pulling will help keep new seed from being deposited into the garden which can be viable for up to 60 years. In the fall, you can spray the lawn with a 2,4-D product.

9. How do you control purslane in the garden?

A. 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.

Gorgone Checkerspot Caterpillar

Gorgone Checkerspot Caterpillar

10. This caller has tiny, dark colored worms on her black-eyed Susan plant. She has used some Eight but she still has some. The leaves are also turning gray, how can she control the caterpillar?

A. This could be a checkerspot caterpillar. It is commonly found on sunflower, which is a closely related species of plant to this black-eyed Susan. This becomes a good pollinator butterfly. If she can relocate the caterpillars it would be best, or the Eight will just take some time to fully work on the caterpillars. The gray on the leaves is likely due to downy mildew or powdery mildew, not the caterpillars. Caterpillars will only chew holes out of the leaves, not leave any gray coloration to the leaves. Downy or powdery mildew are not very harmful to the plant and don’t need to be sprayed. In the fall, cut down the plant and discard the infected plant material so the disease is minimized for next year.

11. A caller has an ash tree that is about 15 years old and the outside leaves are now turning brown. What is wrong with it?

A. This could be due to leaf scorch due to the hot, dry conditions we have been facing lately. The tree should be fine, it will likely look rough the rest of the year. Make sure the tree has a mulch ring and that it is being watered for about an hour weekly with a sprinkler or slow trickle from the hose.

This caller also wondered about cougars in the area. He said he has seen a cougar with 4 cubs in the area. Will the cubs all stay here or will they move through to somewhere else?

A. Males can travel many miles and across the country. Females will stay around if there is food available and if a male doesn’t chase the female cubs away. The male cubs will likely move on when they get old enough to travel alone.

12. A caller has a tree that is pushing its roots up to be exposed out of the soil. What can be done about this?

A. Mulch will be the best option for these roots. The mulch will keep you from mowing over the roots which can damage the roots. Do NOT add soil on top of these exposed roots as that can limit oxygen for those roots and eventually kill the tree. You can make the area into a perennial garden under the tree, but do not raise the soil grade to do so and do not damage the roots to do so.

13. The final caller of the day wants to know why black crappie would be larger than white crappie?

A. This could be due to genes. The color gene may be linked to the size genes. So as the color is changed genetically, so is the size. It could also be that the predators in the area this caller was fishing in preferred eating the white crappie rather than the black crappie, causing only the smaller white crappie to be left with the larger black crappie. There are many factors that could lead to this difference in size between the 2 different colored crappie.

Attack of the Beetles

JB Damage

Damage from Japanese Beetles

This year, like always, we are facing insect issues in our lawns and gardens. It is important to remember that not all insects are bad, in fact the majority of all insects are beneficial in some way. However, when they are found in large populations or damage our plants, or both, we get concerned.

 

Soldier Beetles

Soldier Beetle

Soldier Beetle, Photo from Soni Cochran, Lancaster County Extension Assistant

Soldier beetles are common this year. These are the yellow beetles found in large quantities throughout the area this year. They are often confused with fireflies because they are both beetles without hardened elytra, like many other beetles, and they are similar in appearance. The soldier beetle we are seeing is golden in color with a black spot on each wing on the back. They are commonly found around Linden trees as well as many other flowers. There is no need to control soldier beetles because they are great pollinators and will not harm our plants or us.

Japanese Beetles

Japanese Beetle, 7-16 Acreage

Japanese beetle adult on the left side and grub on the right side, photos from Jim Kalisch, UNL Entomology

Japanese beetles have been more of a problem for southeast Nebraska over the past couple of years than they had been in the past. This is an invasive insect from Japan. Japanese beetles are problematic insects as both larvae and adults. The larvae are a type of white grub which 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. 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. 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.

Grubs can be controlled with chlorantraniliprole or imidacloprid in June. Adults can be controlled with systemic insecticides such as imidacloprid or dinotefuron around Mother’s Day to give the products time to get throughout the trees and shrubs being treated. Currently, no systemic insecticides can be used on Lindens though, due to the damage to pollinators. Tempo and Bayer Advanced Lawn & Garden Multi-Insect Killer (cyfluthrin), Ortho Bug B Gone (bifenthrin), or Sevin (carbaryl) would be a few other options that can be used on Lindens and others. These options will only work for about 2 weeks so they may need to be reapplied.

Blister Beetles

blister beetles, K. Jarvi

Black and gray blister beetles, Photos by Keith Jarvi, Emeritus Extension Educator

Blister beetles were a real problem in our vegetable gardens last year, and they are back. Blister beetles are ½ inch long, powdery gray colored beetles with black antennae. They can feed on our tomato plants as well as some other vegetable crops. They can damage our plants, but they are also beneficial because they feed on grasshopper eggs. If you find them in your garden, you can treat with general insecticides such as sevin or eight. Be careful handling these beetles, some people develop blisters after handling them.

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.