This is the Q&A for the Yard and Garden show for May 17, 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: Kathleen Cue, Dodge County Extension Educator
1. The first caller of the show has a bur oak and a pin oak that have both been very slow to green up this spring and now have turned brown. Is there something wrong with the trees?
A. The browning of those trees is most likely due to the formation of catkins, which are the flower structures of the oak trees. Those turn brown when they mature then will fall from the tree. It may look bad, but it is normal for the tree. They are slow to green up this year due to the cooler spring we have had, they will be fine.
2. A caller has a fishing pond that now has a layer of moss on the edge. He sprayed it with copper sulfate in mid-April and that seems to have not worked for this. What can he do to control it?
A. Copper sulfate is a recommended product for controlling this type of algae on a pond. It can be used when growth first becomes visible. Be careful applying too much of this in one season because it can cause a fish kill if sprayed in too high of a dose. However, when this caller sprayed, it may not have been actively growing so the copper sulfate would not be as effective. A second application could be applied now that it is actively growing. Another way to control this would be to use a rake to pull the majority of this algae out of the pond without having to reapply the chemicals and not risking any problems with the fish.
3. This caller has miniature Iris’ that are now done blooming but they need thinned and divided. Can this transplanting be done now?
A. Yes, it would be fine to divide and transplant these Iris’ now. It would be best to cut off the seed heads prior to dividing so the plants put energy into producing roots not into seed development. Be sure to keep the ground evenly moist after this because the plants will not have a good root system in place, but don’t overwater.
4. A caller was gifted some spring-blooming bulbs that were purchased last fall. Can they be planted now?
A. It is best to plant spring-blooming bulbs in the fall. They could be stored over the summer in paper bags with peat moss in a cool, dark location such as a basement and then they can be planted in the fall like normal. However, because they were purchased last fall, it would be best to plant them now to let the roots grow over the summer months. There is not a guarantee that the bulbs will survive with either of these methods, but they will likely dry out if left out of the ground for a year.
5. This caller has pine trees that died due to pine wilt. He now has volunteer scotch pines coming up in the pasture, will they be immune or resistant to the disease?
A. No, all scotch pines will be subject to the disease, they will not become resistant. Volunteer scotch pines can survive for about 10 years before the disease affects them.
6. A caller has Iris’ that look good and are starting to bloom, but all of a sudden all of the leaves have spots on them. What is it and what can she do to manage it?
A. This is most likely from Iris Leaf Spot, a fungal disease. This is best controlled through sanitation such as removing infected leaves and cleaning up all of the leaf litter in the fall to remove the overwintering site. Also, be sure to water from below the plant rather than over the foliage. If the plants have grown together, it would be best to space the plants out more by dividing and replanting. Fungicides can be used when these practices are not working. Copper fungicides would be best.
7. This caller has a sunset maple that is about 25 feet tall and one half of the tree turns red earlier in the season in the fall while the rest of the tree stays green. Now that side of the tree that turns red first has very heavy seeds and isn’t looking very healthy. What, if anything, can be done for this tree?
A. Stress will cause a tree or even a portion of a tree to go into early fall color. Stress is also one of the reasons that we are seeing the heavy seed production this year in maple trees. During the discussion, it turns out that there is a stress fracture and included bark on the trunk due to co-dominant branches. In this area, there is likely decay and that is problematic on the tree. There is no good way to fix this on the tree now that it is so large. One half of the tree could be pruned off to reduce the damage from the included bark and co-dominant branching. It would take a long time for the tree to recover from this and it will look a little odd while it is recovering from this pruning.
8. A caller reseeded their lawn last fall. It was planted so it got hit by frost and did not survive. Can he spray his lawn and reseed now?
A. The weeds can be sprayed now, but it is a little late now to overseed for this spring. The fall seeding was a little too late and with the early snow we had in October, the grass was not able to survive at such a young state of growth. A similar situation would happen if seeding now, but with heat instead of cold. It would be best to overseed in late August to early September to ensure good growth before frost. For now, he could cover the ground with an annual ryegrass to keep the weeds down. When he does overseed in the fall, he can use a mesotrione product such as tenacity at seeding without harming the seed and killing off the weeds.
9. Can daylilies be planted on the south side of the garage or will it be too hot for them there?
A. Daylilies can be planted in full sun on the south side of a building and they will thrive in that location. They are tough plants. It would not be too hot for them there.
10. This caller has small holes around his sweet corn. Sometimes the seed is gone and sometimes the new plants are cut off at the ground level. What would cause this?
A. This could be from a couple of things. The plants being cut off at the ground level could be from cutworms. Cutworms can be controlled with sevin sprayed or dust sprinkled around the base of the plants. It could also be from voles or even turkeys. If voles, a snap mouse trap can be used in the runs or around the plants where they are seen. If turkeys, there isn’t a good control for them. The problem shouldn’t last the whole season.
11. Finally, a listener texted a picture of a lawn weed to the radio station and wanted to know what it is and how it can be controlled?
A. This is knotweed. It can be controlled with a 2,4-D product.