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.