This is the Q&A for the Yard and Garden show for July 8, 2016. 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 5, 2016. 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: Dr. Paul Read, Viticulture Specialist for Nebraska Extension with Guest Intern Vivian from China
If you enjoy reading my Q&A from the show each week, take my quick survey at: http://go.unl.edu/9b24 and be entered to win a free plant book or some free UNL gifts.
1. The first caller of the day wanted to know if they can prune the Cleveland Pear tree that has branches that are low and too tight to the trunk?
A. The best time for pruning a tree like this would be while it is dormant. For a situation like this where the caller is only removing a few branches to help with the growth of the branches and to reduce future problems with the tight branch arrangement it would be fine to remove them now. It would be better to remove branches like this before they break in a storm due to weak attachment to the trunk.
2. A caller has Anjou pear trees that were planted in 2013. Now the bark from the graft union up about 10-12 inches has the bark peeling and now has some black leaves. What would cause this?
A. This would be from sunscald. There is no way to fix sunscald once it occurs. Don’t paint the wound with anything, allow it to heal itself. The black leaves could be due to fireblight. You can cut 6-8 inches past the diseased portion of the limb to cut the fireblight off the tree. The black could also be anthracnose which is not damaging to the plant and there is no need to spray anything for anthracnose.
3. This caller has an oak tree that is dripping sap on the vehicles parked under it. What would cause this?
A. Aphids feeding on the leaves of trees will excrete honeydew that can drip on vehicles underneath the tree. Aphids are not very damaging and have a lot of predatory insects that feed on them. They can be sprayed with sevin or eight or another general insecticide, but they should fade out on their own with predator insects.
4. A caller has blue spruce trees that look dirty but the tips are still green. What would cause this?
A. This is most likely due to environmental stress from the heat and humidity. If the ends of the branches are still green, the tree will be fine. Make sure your tree has a mulch ring around it and that you keep it well watered in the heat of the summer.
5. This caller has a patch of lilies where a quarter of the patch has only grown to be about 6 inches tall for the past 2 years. The rest of the patch looks good, but this area doesn’t look healthy. Can these be improved?
A. This could be due to hardiness in some varieties that are only suitable for our environment for a couple of years. It also could be due to some bulb mites. It would be a good idea to dig up some of the bulbs to see if they have any damage on the bulbs.
6. A caller has a pine tree with a lot of sap on the branches and the grass in the lawn won’t green up. Why is this?
A. Woodpeckers or insects feeding on a pine tree can cause sap to leak from the wounds left behind. The insects can be controlled with bifenthrin or permethrin (eight). If it is woodpeckers, the damage is minimal and will not cause any problems to the tree. Check how much water the lawn is actually receiving by using catch cans during the water intervals normally followed. Lawns need 1 1/2 inches of water per week. If the water is fine, there are a lot of fungal diseases in the lawn, it could be one of those. Fungal diseases in the home lawn are usually sporadic and therefore don’t require fungicide applications.
7. This caller lives on an acreage surrounded by farmground. She is considering growing grapes on this large plot of land. Are grapes easy to grow and would grapes have a benefit to the wildlife in the area?
A. Grapes are a large commitment, especially if you plan to sell products from them. You can be successful with only a few plants for the family to use for grape production. A few good choices for this area would include Frotenac or Valiant. The first year the grapes would need extra care, but after that they would be more self-sustaining. Deer will feed on the foliage. If you decide to grow your grapes for commercial use, register your acreage with the driftwatch website at www.fieldwatch.com to help avoid problems from drift since grapes are very sensitive to drift damage.
8. A caller has strawberries that were planted and now have very small fruits and the plants are not making runners.
A. Everbearing strawberries are typically very small for fruit size. You might try planting some newer varieties that are June bearing to get larger fruits. Some good choices would include honeoye or albion or sparkle.
9. This caller has an ash tree that is 7 years old and the tree snapped off in the wind. There is mold in the trunk and it is suckering. What can be done to plant a new tree?
A. You can get a company to come in and grind out the stump or rent a stump grinder to do it yourself. The suckers that keep growing back will continue to for a few years, they can be cut out and treated with a roundup or 2,4-D product. You can plant a new tree within just a few feet of the old tree, since this wasn’t a very large tree yet.
10. A facebook photo came in with a odd structure that appeared by a tree. What is this?
A. This would be a stinkhorn fungus. They are not harmful to the plants growing in the area. There is not control other than mechanical removal of the fungus. Do not eat these as they are not edible, they would be a poisonous mushroom.
11. The last caller of the day has tomatoes in a raised bed. When they ripen for harvest, the end of the tomato seems blighted. What would cause this?
A. This is blossom end rot. It is a calcium deficiency that develops in our plants in drought situations because calcium is only available to plants after it has been dissolved in water. There is no control for this, it should only last for a few weeks early in the growing season and then the plants should grow out of it.