Yard & Garden: July 17, 2020

This is the Q&A for the Yard and Garden show for July 17, 2020. 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 31, 2020. 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, Lancaster County Extension Educator

2015-07-17 10.51.40
Green June Beetles

1. The first question of the show was from a listener who brought green beetles into the studio for identification. These were found in his trees and he wants to know what they are and how they should be controlled?

A. The beetles were Green June Bugs. These are a native insect species that can be found on many different plants. They can be ravenous feeders in grapes and occasional feeders in vegetable gardens, but on trees they are not very damaging. If they feed on vegetable gardens or grapes, you can use sevin or eight on them.

2. This caller has a Linden tree that is 12 years old that is losing leaves now. The leaves turn brown as well. They did recently give it a deep watering, but that isn’t seeming to help. What is wrong with the tree?

A. Check the tree thoroughly for Japanese Beetles, it is one of their favorite plants to feed on. They will feed heavily causing the leaves to look like lace and then the leaves will turn brown. The trees can look fully brown by late summer. If it is, you would want to work with an arborist to spray the tree. Be very careful with what you spray lindens with and when you spray them to not harm pollinators. If the leaves don’t have holes in them, it could be from a stem girdling root which cannot really be fixed so late in life.

3. A caller has peppers that have white spots on them. What caused this?

A. This is likely due to drift from Roundup or another glyphosate product. Wind can drift the particles which will leave white, irregularly shaped spots randomly across the leaves. If it was from a disease it would be more tan or brown in color.

4. This caller has tomato plants that are loaded with green tomatoes that are not turning red. What is disrupting the maturation process of the vegetables?

A. When the temperatures are so hot, as they have been, the fruit ripening process is slowed down or stopped completely. They will mature when the temperatures break to cooler temperatures.

5. A caller wants to know when she can harvest wild flower seeds to reseed in a new area in  her landscape?

A. The seed needs to fully mature while still on the parent plant. Make sure the seed head is dried and brown, then you can cut off the stalk and move the seed to the new location. If you can easily shred the seed  head with your fingers, the seed is mature and can be reseeded in a new location.

6. This caller has tomatoes and beans with troubles in the garden. The tomatoes have brown leaves on the bottom of the plant, what is causing that? The beans have flowers on them but no fruit has been set, why are they not producing beans for harvest?

A. The tomatoes likely have early blight, it is a common fungal disease that we are seeing this year. You can just remove the infected leaves and discard them to reduce the disease. If the plants still have troubles, you can spray them with a copper fungicide if necessary.

As for the beans, the heat is likely delaying fruit set. In temperatures this hot, the flowers can develop but the pollen can be killed so fruit will not set. Give the plants a little more time and they will start producing beans once the temperatures cool off.

7. A caller has columbines that are in a garden bed overrun by weeds. She wants to redo the bed to help get rid of the weeds. When is the best time to dig them up and do some work then replant them?

A. The fall or spring would be a good time to dig up, divide, move, and redo the garden space. When the temperatures are cooler. When we move or divide plants we break their root system, making it harder for the plants to get the needed moisture to survive. It is best to do these things when it is cooler so the drought stress isn’t as high.

8. This caller has tiger lillies that were knocked over by the wind and broken. Can the seed be moved to another location?

A. Make sure that the seed matures on the plant. If the stems were broken so the plant is not still maintaining the seed, they may not be able to be reseeded to a new location because the seed wouldn’t be mature. If that is the case,  you can divide the plants and plant some in the new location. September would be a good time to do this.

9. Is there any post-emergence herbicide that can be used in an asparagus patch that won’t hurt the asparagus?

A. No, there isn’t anything for post-emergence. You can use preen that is labeled for use in the asparagus in the spring prior to germination of the annual weed seed and again in the middle of the summer. This will help with annual weeds. For perennial weeds you can use roundup or another glyphosate product early in the spring prior to emergence of the asparagus. You can also use it after the final harvest of the year. Cut out all of the stems of asparagus and pull mulch or the soil up over the stems so no green is showing, then spray the roundup over the bed to kill the weeds and not harm the asparagus.

10. This caller has an old lilac that has leaves that look bad. Can it be cut down now?

A. It can be cut back with a rejuvenation cutting in September. This is when the lilac is cut back to 6-8 inches above ground. This will help to rejuvenate the plant to newer, healthier growth. This method will disrupt the flowering for a year or two, but it will eventually flower again. The lilac can also be caned out every year by removing 1/3 of the largest, least productive canes every year to remove those canes that are not improving the health of the plant.

11. A caller asked why his tomatoes look good but have no fruits or flowers at this point? It was hit by herbicide drift a month ago, but they have grown out of that.

A. The heat is pushing back maturation of the fruits right now. However, if your plants have no fruits at all, the herbicide injury could have stunted the plants. The combination is pushing back maturation of the fruits. Eventually they will flower and produce fruits, just give it time.

12. The last caller of the day asked about green beans that are blooming but have no fruits. What is causing this?

A. The heat is likely delaying fruit set. In temperatures this hot, the flowers can develop but the pollen can be killed so fruit will not set. Give the plants a little more time and they will start producing beans once the temperatures cool off.

*Reference to commercial products or trade names does not imply endorsement by Nebraska Extension or bias against those not mentioned.

Yard & Garden: May 29, 2020

This is the Q&A for the Yard and Garden show for May 29, 2020. 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 31, 2020. 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: No guest host due to COVID-19 and social distancing

1. The first caller of the show has tomato plants that now is developing “skinny” leaves. What is wrong with them?

A. The leaves are skinny and deformed. This is likely from herbicide drift, it is hard to say for sure without seeing the plants, but it sounds most like herbicide drift. This has started to become a problem again this year due to the change in weather. As we warm up, we see more problems with 2,4-D and dicamba products that turn to a gas and move to non-target plants. Tomatoes are very sensitive to drift from 2,4-D or Dicamba products. They should grow out of the damage, however because we don’t know exactly what product hit these tomatoes there is no way to know for sure when the product will be out of the tomatoes. I can’t say when or if these tomato plants will be safe for consumption this year.

2. This caller has a very large hosta. When can it be divided?

A. Early spring is the best time to divide hostas, once they have emerged from the ground but before the heat of the summer. It might be a little late to divide the plants this year due to the hot weather expected next week. If they are divided now, be sure to keep them well watered.

3. When can oaks and maples be pruned?

A. The new pruning recommendations show that pruning is best if done in late spring, so late May to early June for Nebraska. Now would be a good time for most trees, however, oaks are susceptible to oak wilt if pruned during the summer months. It is best to wait until fall, September or October, to prune oak trees to avoid this disease. Maples, can have a heavy sap flow in the spring, they can be pruned now, but may leak sap, sometimes large quantities. They would be better to prune in the fall also.

4. A caller was going to use Grass-B-Gon on some weeds she recently hand-pulled to reduce the hand-pulling in the future. How long should the regrowth be before she applies the grass killing product to her landscape beds?

A. As long as you start to see some new, green regrowth, the product should work. According to the label, it should be applied anytime weeds are actively growing, which would be when you see them green up again around your landscape plants.

5. This caller is on her second round of planting tomatoes and they are turning yellow again. She planted the first in late April and then again recently. In the new planting one plant is starting to turn yellow. She is using straw mulch on most of the plants but is using grass mulch on the one plant that is turning yellow. What is wrong with her plants?

A. The first round of plants were planted too soon and we saw quite a bit of cold weather later in the season this year than many other years. She did cover the plants on the sides, but left the top exposed. Frost would have settled down onto the plants and killed them. The new plants are doing fine except the one plant that has grass clippings on it. The lawn has been treated with broadleaf weed control as well as crabgrass control this year. The labels will tell you not to use the clippings on the garden for the season or for a period of time. If that isn’t being followed and this is the one plant that is looking bad, I would assume that the grass clippings are the problem. Be sure to use clean grass clippings or use straw for all of the plants.

6. A caller pulled 3 mature barberry bushes with a pickup truck and then decided to replant them after all. What should be done to keep them alive? Should they be fertilized?

A. Pulling these plants out with a pickup truck and chains would have drastically damaged the cambium layer which can reduce the flow of water and other nutrients through the plant. They were also kept out of the ground for a week before being replanted. These plants could pull through if they are tough, but you will need to make sure they are kept moderately watered. Don’t overwater, but don’t allow the plants to dry out either. A slow trickle for about 10 minutes a couple of times per week will help to rebuild the roots. Do not fertilize them. Fertilizing a stressed plant can further stress the plant. Only time will tell if they can survive.

7. This caller has lilacs that are looking bad and didn’t bloom well. What can be done to help them? When can they be pruned?

A. Sounds like this lilac is in need of a rejuvenation pruning. This is where you cut the plant off about 6-8 inches above the ground level to rejuvenate the growth. It will reduce insect problems and push new, young growth to provide better blooming and have a healthier plant. This can be done in the fall for best results.

8. A caller had bagworms on her cedars last year. She also noticed a lot of praying mantis egg cases, she knows they are a good predator.  Are the praying mantis’ helping to control the bagworms?

A. Praying mantis’ are not a major predator of bagworms. They prefer feeding on aphids and others.

She also wondered about her forsythia that was injured by the late frost this year. It didn’t bloom this year and she had to cut back some of the branches. Will it bloom next year now or did this damage the blooms for next year as well?

A. The blossoms are set on the new growth that will form this summer. As long as they are pruned back within about 3 weeks after their bloom period, they will still bloom next year. This is why we prune forsythia just after they bloom rather than in the late winter. This forsythia should still bloom next year.

She had one final question, how can she control a clover-type weed growing profusely in her iris beds?

A. This will be difficult to do without harming the iris plants. She could spray with Roundup using a piece of cardboard as a barrier between the weeds and the iris plants or she could use the “glove of death”. This 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.

9. What can be done to control elm saplings in a windbreak?

A. You can go through and cut off the trees and follow that up with a stump treatment using either 2,4-D or a glyphosate product, such as Roundup. The Roundup would be better this late into the year to avoid volatilization issues from the 2,4-D in the heat. Use the concentrate and just paint it on to the freshly cut stump for best control. Do NOT use Tordon, that will likely kill the spruce trees, and it is against label directions.

10. A caller planted grass in the spring. It is getting to about 2 inches tall now. When can he spray the weeds coming in with the grass?

A. You should wait until after 3 times mowing the new lawn before any herbicides should be applied to the grass to avoid injury. However, by that time, it will be too hot to use any 2,4-D products, which will turn into a gas and move to non-target plants and injure them in temperatures above 80-85 degrees. It would be better to just wait it out and spray in the fall to manage the weeds after the turf is more established. The fall is a better time to treat for perennial broadleaf weeds because it is when the plant is taking nutrients back into the root system and it will take more of the herbicide with it. Spray twice in the fall, once in mid-September and again in early to mid-October.

11. This caller has a hydrangea that didn’t look like it was going to live through the late frosts this spring. She did notice that it is finally coming up but it is only about 3 inches tall and is setting blossoms on. Should she remove those or let the plant bloom at such a small size?

A. It would be best to remove those blooms to allow the plant to grow a bit more before trying to bloom. All the energy in that plant would push into flower production, at such a small size, it would be best to allow the plant to build leaves and the root system to help it so it comes back next year.

12. A caller wants to know what to do to keep iris blooms from falling over?

A. Sometimes if the flower is too heavy it can fall over a bit. There are metal rings you can purchase to put in flower beds around plants that fall over to keep them upright, but nothing else will work for this. The flower is just too heavy for the stalk.

13. If branches on a tree or shrub are already dead can they be pruned off now?

A. Yes, dead branches should be removed as soon as they are noticed to prevent injury or damage from a falling branch.

14. The final call of the show asked if they should be fertilizing lilacs that were planted 3 years ago?

A. Fertlilizer doesn’t need to be used on plants that are growing just fine. Most trees and shrubs can get the nutrients they need to survive from our soils. The best thing is to do a soil test prior to adding any soil amendments, nutrients can build up to a too high level which can also damage the plant.

*Reference to commercial products or trade names does not imply endorsement by Nebraska Extension or bias against those not mentioned.

Yard and Garden: July 26, 2019

Yard & Garden blog, 2019

This is the Q&A for the Yard and Garden show for July 26, 2019. 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 2, 2019. 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 question of the show was about catalpa trees. They were pruned in the past, but now they have a bunch of smaller branches growing out of the location where the branch was removed from the tree.

A. The branch that was removed was likely not correctly done. If the cut wounded into the trunk of the tree or left a stump, it would cause the tree to push a lot of new growth like suckering. Make sure that proper pruning cuts are followed and that you don’t leave a stump. Follow these steps when pruning a tree to ensure it is removed correctly with minimal damage and avoid the branch-bark collar to avoid a flush cut which will not heal correctly.

3-step pruning cut
Proper pruning cut, University of Missouri Extension

2. How do you control clover in the lawn?

A. Clover can be found in an under-fertilized lawn. It may be a good practice to fertilize at least one time a year to help the lawn compete with the clover. If treating with chemicals, the fall is the best time of year to treat for broadleaf perennials such as clover, dandelions, and creeping Charlie. Apply a 2,4-D product or one containing triclopyr twice in the fall. Mid-September and again in mid-October is best. Other IPM strategies for controlling clover include mowing high and aeration if necessary.

Co Potato Beetle Pupa 2
Colorado Potato Beetle Pupa

3. A question came in via email about orange things on potatoes. There are tiny orange bugs found on potato plants in her garden. What are they and how can they be controlled?

A. These are Colorado potato beetle larvae. Pull any off that are found and smash them or spray with sevin to control them as they emerge as beetles.

4. A caller has creeping Charlie in their yard. When is the best time to spray for that?

A. When using chemicals, the fall is the best time of year to treat for broadleaf perennials such as clover, dandelions, and creeping Charlie. Apply a 2,4-D product or a product containing triclopyr twice in the fall. Mid-September and again in mid-October is best. Other IPM strategies for controlling creeping Charlie include mowing high and aeration if necessary.

5. This caller has cucumber plants with a lot of flowers but no fruits. Why are these plants not producing fruits?

A. You should check the flowers to see if they are all male flowers or if there are female flowers as well. Male flowers just have a skinny stalk behind the flower. Female flowers have a tiny cucumber behind the flower. If male flowers are all that are present, give it time for the plant to produce female flowers. If both male and female flowers are present, there could be a problem with pollinators. Avoid spraying while bees are active, attract bees with other pollinator plants, put up a bee house to bring bees in. If you are using row covers, be sure to uncover the plants for a while during the day so bees can pollinate the plants.

6. A caller called in with a good suggestion to help with cucumber plants. He grows his on a trellis so they can get better airflow and less diseases. It also makes it easier to harvest the plants this way.

7. This caller has a small hackberry that is 12-14 feet tall with 3 trunks growing together. There are small splits all along the trunk like some type of injury, what caused this and will his tree be ok?

A. These could be spots from hail injury, even from a few years ago. There is nothing to do for hail damage. Most trees will come through just fine. If the damage is intense, the tree could have more problems.

8. Is it too late to trim lilac bushes?

A. Yes, it is too late for general pruning of lilacs. They should be pruned within the first couple of weeks following the flowering period. If a rejuvenation pruning is desired, the fall would be a good time to do that, wait until late September to mid-October for that.

9. A caller who manages a golf course has a couple of Linden trees that were under water for about 2 months this year. They sat in a flooded area of the golf course for this time in the spring. They originally did leaf out but since then the leaves have turned brown. Will the tree be ok?

A. There is likely no life left in these trees. Lindens are not adapted to have their roots that wet for that long. The trees probably had enough energy left in the roots to push out leaves but now have ran out of energy. It would be best to remove those trees and replace them with something more adapted to sitting in water from time-to-time, such as bald cypress trees.

10. The final question of the day was sent via email. This listener has a gravel driveway that is partially sloped. How can they keep the weeds out of this driveway and not harm the grass at the end of the slope?

A. Roundup 365 would be the best option for this. It contains glyphosate as well as imazapic which lasts longer than the glyphosate alone. On the label it states to only apply once a year and to “spray until THOROUGHLY WET”, so for best results spray to this extent. Soil sterilants aren’t recommended because they often run off into adjacent plant material such as grass and kills it. Always read and follow the label when using pesticides.

*Disclaimer ­- Reference to any specific brand named product does not constitute endorsement, recommendation, favoring or implied criticism if similar products are not mentioned by Nebraska Extension in Gage County.  Identifying specific pesticides are for the convenience of the reader and are generally most commonly available.  Always read and follow the pesticide label.

 

Yard and Garden: May 3, 2019

Yard & Garden blog, 2019

This is the Q&A for the Yard and Garden show for May 3, 2019. 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 2, 2019. 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: Dick Campbell, Owner of Campbell’s Nursery

1. The first caller of the show has holes in his lawn that are about the size of a pinky, what would cause that?

A. This could be from either earthworms or wolf spiders. Neither of these will harm our lawns, in fact they are both beneficial. Earthworms break up the soil and add compost back into our soil. Spiders will feed on problematic insects.

2. A caller was wondering about a homemade weed killer that has vinegar, dish soap and epsom salt in it?

A. It is not advised to go with homemade weed killers because there is no research to help with rates, timing, PPE, or other environmental and health risks associated with them. It is best to use IPM to control pests using mechanical and cultural practices first then turn to pesticides that have been approved from the EPA.

3. This caller is having difficulty with a redbud that isn’t blooming. It is 6-7 years old and in full sun, but it isn’t blooming yet. Why is that and can he do anything to get it to bloom?

A. Some varieties of redbuds take a few years before they will start blooming, it could just not be fully mature and ready to bloom yet. Transplant shock can also set the blooming cycle back. It should be over that soon. Also, if it is in an area where the lawn around it is getting a high amount of nitrogen, that could push the tree to leaf out and not push energy into flowering. Give it time and reduce the nitrogen fertilizer applied around the tree.

4. A caller has 2 lilacs. One is blooming fine, while the other is blooming only on 2 branches and the other branches seem to be dead. What can she do about this lilac?

A. A rejuvenation cutting will help to renew this shrub with only 2 live branches. You can cut the entire shrub off at about 6-8 inches above the ground. The new growth will be healthier and it should leaf out better and throughout the whole shrub. It may take a couple of years to rebloom after this rejuvenation cutting, but it will be better in the long-run. Also, be sure to remove any grass growing right up around the trunk of these shrubs. Add a nice 2-3 inch layer of mulch and keep the grass competition out away from the shrubs.

5. What is the best decorative/flowering tree for Nebraska?

A. There isn’t really one that is better than the others, there is a long list of great flowering trees. Crabapples are great spring flowering trees. Make sure that you pick one that is resistant to cedar-apple rust and apple scab. Serviceberries make a great flowering tree or large shrub for any landscape with berries for the birds in the fall. Redbuds are a favorite among many and there is a whitebud which is just a white flowering variety. Magnolias are amazingly beautiful, but they need to be planted in a somewhat protected location to help with flowering in those years with a later frost. Flowering pears can be used, but choose Chanticleer or Cleveland Select to avoid problems with branches breaking due to tight branch crotches.

This caller planted a redbud 6 years ago, but it has since died. What caused that?

A. It turns out that this tree wasn’t purchased from a local source and may have been shipped from the south, which was common with redbuds a few years ago. Once they were moved into Nebraska, they couldn’t tolerate the conditions that were so much different from where they were started and sourced, which was typically the South. This is why it is best to purchase trees from a local grower or a grower that is at the same latitude or further north than where the tree will be grown.

6. Where can you get buffalograss seed or plugs?

A. Campbell’s nursery has both seed and plugs available for purchase, as does Stock Seed Farms in Murdock, Nebraska. Buffalograss is a warm-season grass and shouldn’t be planted until late spring so later May would be ideal. It can be seeded until mid-August so long as irrigation is provided to help with establishment. Soil temperatures need to be 60 degrees F before buffalograss seed will germinate. Plugs should be planted at this time as well.

7. A caller added a raised bed around the tree about 5 years ago and heard us discussing how that shouldn’t be done. What can be done now?

A. Adding a raised bed around an existing tree can end up suffocating the tree. Before the raised bed, the tree was planted at the correct depth, after the raised bed, the tree is too deep. It will take between 5-10 years sometimes before any damage starts to show up in the tree. It is likely that once the tree does start to react to this change, you will see top dieback. You can try to remove the excess soil now, but it may be too late, the tree may still die.

8. When do you spray for bagworms?

A. They will hatch at different times in the year, it is weather dependent. Starting in late May, check weekly for the small bags to begin to show up on the trees. When the small bags show up and until they are up to 1/2 inch in length you can spray. Tempo or Bt would be best for control.

9. This caller has an area on the north side of their house in full shade that she would like to plant shrubs into. What can of shrubs can she plant in full shade?

A. There are some euonymus shrubs that could be planted there. This is the same genus of plant as burning bush. Summer sweet would grow well in the shade. If there is some sunlight, many hydrangeas would grow well there.

Termites
Subterranean Termites, Picture from UNL Entomology

10. A caller has concerns about termites coming from wood mulch. Will termites come from the mulch into the home?

A. It really isn’t a concern that termites will be brought in with mulch. The termites would be either cut up with the mulch or they would dry out quickly in those small pieces of wood. They have a soft body and will dry out quickly if not within soil or wood. If the wood mulch is piled up so high to where the mulch is touching wood siding, it can be a pathway for the termites to enter the home. However, mulch is recommended to only be 2-3 inches deep and most concrete foundations will go higher than that. Also, if you have had termites in the past, you should be working with a pest control company for termite control and the chemicals will manage the termites from the mulch.

11. The final question came to us from a Facebook post. This caller has a spot in his lawn that had a sidewalk in 1993, but even still it seems to dry up quickest in the summer and you can see a visual difference in the area where the sidewalk was in comparison to the rest of the grass.

A. This soil was severely compacted to add the sidewalk and still has not gotten better. They also add sand to build concrete on top of. I would suggest aerating annually and spreading compost over this area after the aeration. Over time, this will help to loosen the soil and to add organic matter back to the soil. Otherwise, you can dig it all up again and put in new soil that is high in organic matter and reseed overtop of that which would be much more work.