This is the Q&A for the Yard and Garden show for May 26, 2017. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through July 28, 2017. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.
Guest Host: Laurie Stepanek, Forest Health Specialist from the Nebraska Forest Service
If you enjoy reading my Q&A from the show each week, take my quick survey at: http://go.unl.edu/44qr and be entered to win a free plant book or some free UNL gifts.
1. The first caller of the day has a bleeding heart plant that she wants to plant but the area she wants to plant it in is full sun all day. Will it be ok in that environment?
A. No, this is a shade plant. When plants that need part to full shade, such as bleeding hearts, are planted in full sun, the leaves will begin to burn as the summer goes on and it will not survive as long or produce as many flowers. The east side or the north side of a building is best for these plants where they may have morning sun but are protected from the afternoon sun.
Boxwood with winter desiccation, photo by Lindsey McKeever, Gage County Extension
2. A caller has some boxwoods that looked good in February but now have areas of dying leaves. What is this from and can it be fixed?
A. This is from winter desiccation. This winter was very dry and caused a great deal of damage to a lot of different evergreens and broadleaf evergreens. During the winter our evergreens are still transpiring. When we don’t get additional moisture naturally and the transpiration exceeds the moisture absorbed by the roots, the plants will show winter burn or winter kill. This can be pruned out and many plants will be just fine. However, if the damage takes the pruning into the part of the plant where leaves are absent, then it may be time to replace this particular shrub. Boxwoods are often damaged in Nebraska, so a Yew may be a better replacement.
3. This caller has a mailbox in full sun just off the street that is very hot for plants. Is there a type of groundcover that will survive and do better in this location than a rose moss has done in the past?
A. Sedum, Rose Moss, Dianthus, Rock rose, Cacti, Ice Plant, Basket of Gold, Wall Rock-cress, Hens and chicks, or Catmint could all be used in this area and will thrive. It may take a few of these plants to fill in, but they will be great after time.
4. A caller wanted to know what to do for transplanting and preparing a site for grapes?
A. Here is a good guide from Oregon State University on growing grapes. You can also find a lot of great information on grapes and other fruits from Connie Fisk on the Food.unl.edu website
5. A caller wants to know why his fruit bushes are not growing well? He is growing boysenberry, raspberry, and others that are planted in part shade on the East side of a building.
A. All of our small fruits would need to be planted in full sun. Try moving them to a location with at least 6-8 hours of sunlight per day, afternoon sun is best.
6. This caller has oak trees that have signs of 2,4-D drift. What can he do to help them? Will they survive?
A. These plants may drop their leaves and push new growth to help overcome the damage from the herbicide drift. There is not much you can do to help them through other than to keep the trees otherwise healthy. Ensure they are getting correct waterings and keep a mulch ring that is 2-3 inches deep. This damage may have also been from Dicamba, which is an active ingredient in Trimec and is causing many problems in our oak trees as well as many other tree species. Make sure when you apply pesticides you are reading and following the label, spray with low wind and cooler temperatures. Dicamba can turn into a gas and move to non-target plants in temperatures above 80 degrees. It can volatilize for up to 72 hours after application.
7. The cherries on a tree bloomed and were developing, now the cherries are brown and dead. What caused it? Can anything be done to fix the problem?
A. This could be due to a frost issue or due to brown rot. There is no way to fix it now that it has happened. If it is brown rot, you might try an Orchard Fruit Tree spray next spring to reduce the disease.
8. A caller has swamp white oak trees that leaves are curly on the old growth, but the new growth looks normal. What would cause this?
A. This is from a herbicide drift issue. The first flush of growth was affected by the herbicide damage but the new growth would be free from damage. Our trees will push secondary growth after being hit by pesticides and the new growth will be fine. There is nothing to do for it and the tree should be fine.
9. Do containers need new soil every year?
A. It is best to replace at least the top 4-6 inches of soil with new soil in containers each year to ensure there are enough nutrients to help the plants through the season. After one growing season, in a container, the plant will use up the majority of the nutrients in the soil.
10. A caller has a Japanese Maple that was growing in part shade, but many of the trees shading it were removed and now it is mostly in full sun. The bark on the south side is peeling and the branches on the south side are dying. Can it be saved?
A. This is a great deal of environmental stress to the tree that now cannot be changed. The tree has little chance of survival at this point.
11. Can herbicide drift come from granule products as well?
A. The granule drift comes from the wind blowing the actual granules, or the soil that is attached to the granules, to non-target plants and locations.
12. This caller has tomato plants growing in containers and the leaves, mostly the lower leaves, are turning brown. What can be done for this problem?
A. This is mostly due to the weather conditions we have had the past couple of weeks. Excessive rains and cloudy days have caused a slight fungus to affect the lower leaves. Pinch the damaged leaves off and ensure you water below the plant and it should recover with better environmental conditions.
13. A caller has the galls for Cedar-apple rust on his cedar trees and he also has apple and pear trees. What should he do to control this disease?
A. These are the galls that have the spores for the disease in them. In the spring, when we get rain, the galls open up and the spores are released to other trees nearby. This is a harmless problem on the cedar trees, but not to the apple and pear trees. If you have susceptible apple and pear trees where you have seen red to brown spots on the leaves in past years, you need to spray now with a fungicide spray.
This caller also has a silver maple tree with large holes that squirrels are living in. Can you control the squirrels so they don’t live in the tree?
A. There is no good way to control squirrels in the tree. Even if you trap for a couple, there are always more. The bigger concern in this situation is the decay happening in the tree. When large holes open in the tree, like this, there is decay happening in the tree. It would be best to have an arborist come in and inspect the tree to ensure it is safe.
14. This caller had 3 questions: Why are his vegetable plants already producing flowers and fruits when they are still very small? He planted peppers early and wants to fertilize them, what should he use for fertilizer? He is starting a bee-friendly prairie area that is being overrun by brome grass. What can he do to control the brome grass?
A. Many of our vegetable plants are stressed from recent rainy and cold environmental factors and are pushing flowers and even fruit on small plants. Snip or pinch off those flowers and fruits to allow the plants to push growth into the plant rather than into the production of fruits. Fertilizer can be applied as a side-dress to pepper plants now, but don’t fertilize with too heavy of Nitrogen and discontinue fertilization after this treatment. Too much nitrogen at the time when the plants should be producing fruits will cause them to produce more green, leafy material and not fruit production. Any general vegetable garden fertilizer will work. Brome grass can be controlled among broadleaf plants with grass-b-gon products to kill the grass but not the desired broadleaf plants.
15. A caller has 3 Austrian Pine trees that were spaded in 3 years ago. One isn’t growing as fast as the others and looks stunted in comparison. Should he replace the one smaller one by having a larger tree spaded in to improve uniformity?
A. The smaller tree may still pull through. However, if you have a new tree spaded in, you will have the same problem because spading a larger tree causes a lot of stress to the tree and it will take a few years for the tree to get through that stress period. So you will have the same problem with a new tree. If the smaller tree has good growth, leave it, it should get back into pace with the others.
16. This caller had some cedar trees removed a few years ago and is still having troubles getting new plants established in that area. How long will it be before he can get new plants to grow there?
A. There is no good estimate of this. The new plants are battling roots and compacted soils from years of the cedars being there. Add compost to the soil and mulch it for a year or two to help improve the soil.
17. The last caller of the day has a pin oak with yellow leaves. Why is this?
A. This is due to Iron Chlorosis, which is a deficiency of the nutrient Iron for the tree. This is very common in pin oaks in our area due to the high pH in our soils which holds on to the iron making it less available and harder for our plants to get. You can do trunk injections of iron, but that is only effective for 3-5 years each time. Iron granules are not very effective and we don’t recommend putting nails into the trunk of a tree due to the damage it causes. This is a young tree that will battle this problem its whole life. It might be time for removal and replacement with a different oak that doesn’t have so much trouble obtaining iron, such as red oaks.