Wednesday, May 20, 2009
Dying oak leaves only one option
John Arbogast
Landscape consultant John Arbogast answers your questions every Thursday. Send questions about your lawn, garden, plants, or insects to:
Dear John
5102 Greenfield St. SW
Roanoke, Va. 24018
Or send an e-mail. Answers will be given only in this column. Please don't send pictures or samples.
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Q: I came across your Web site searching for a cause that might be killing my oak tree. It's very large. I have had moles around this tree for about two years as well as ants. I think I have gotten rid of both for now but one side of my tree is pretty dead. Could these moles have killed it on that side where they were and will it survive or should I have it cut down because it is fairly close to my house?
A: Survival of your oak tree is questionable. Without being able to see your tree, I can’t tell you how much risk the dying oak poses to your house. But having any dying tree cut and removed sounds like a safe plan.
The dead branches are there because there is something bad going on, possibly below ground, which has prevented moisture and nutrients from being supplied to those branches.
Moles are insect eaters, not plant or root feeders. They have not killed your oak. Their presence, though, could indicate that there is root decay, and the moles are feeding on ants, worm and grubs that are present as part of the moist, decay process. The ants certainly haven’t been there to provide food for the moles, but this is how nature works.
Moles make tunnels that can be used by field mice, also known as voles. These critters can feed on and damage tree bark and roots, which could explain the dead branches.
Arrange for a local tree expert to examine your oak and make a better appraisal of the tree’s future than can be done over the Web.
Q: I have tiny bugs eating my strawberries before they ripen. What can I do? Opelika, Alabama
A: First, identify the pest. Take a fresh sample of some of the bugs to a local expert and get a control recommendation that is legal and safe.
I do not know of an insect that feeds on developing strawberry fruits in Virginia. I am aware that slugs or snails can feed on moist strawberries at night. I believe that turtles can eat parts of ripening strawberries. But I don’t have a blanket recommendation for unknown tiny bugs damaging young strawberries.
It might be that there is too much moisture being held around the developing berries. These tiny insects could be there because of high humidity, indicating that the strawberry plants need to be divided and thinned out after berry harvesting.
