
                         Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: SUNDAY, June 20, 1993                   TAG: 9306210337
SECTION: HOMES                    PAGE: B-1   EDITION: METRO 
SOURCE: John Arbogast
DATELINE:                                 LENGTH: Medium

VEIN POCKET GALL POSES NO THREAT TO OAKS

Q: I have an oak tree in my front yard that has a problem. All the leaves have curled on it this spring. The leaves have gotten some kind of puffy growth along the middle vein of each leaf and also going out from the middle vein along the vein that goes to each finger of the oak leaf. Other than the puffy growths, the oak leaves are still green. I called two different tree companies about this. The company that was to get more information about this problem never got back in touch with me. Do you have any idea why the leaves on this tree are this way? What should be done? M.C.L., Roanoke

A: This sounds like "vein pocket gall," and it is not a serious threat to your oak. Galls are abnormal growths of plant tissue induced by insects or other organisms. Various galls have been common on the leaves of landscape plants this spring, based on samples brought to the Roanoke Extension Office.

The vein pocket gall has been one of those found, so you are not alone. For readers who have oaks that have not been afflicted, vein pocket galls are hard, tan-colored swellings along the central vein and the major side veins of pin oak. The formation of the swollen areas along the veins causes the leaves to curl. This particular gall is caused by a tiny insect called a midge, which lays its eggs in the young leaf tissue.

The presence of vein pocket galls on your oak leaves requires no treatment. Even though the leaves may be somewhat curled, they will still make food for the tree as long as they are green. Controlling gall insects is difficult anyway. Also, any treatment that you or a well-meaning tree service might ap JOHN ARBOGAST ply after galls are already present is useless, because those swollen areas will not go away even if the parasite is killed.

Q: For the second year in a row, my peonies have lots of tight buds, but they aren't opening. There are lots of ants on them. The foliage is strong and healthy, and they get a good amount of sun. Any suggestions? L.W., Lexington

A: Consider these most commonly occurring possibilities that can explain the failure of peonies to bloom even though the foliage looks healthy:

Roots buried at the wrong depth (the eyes should be about 1 to 1 1/2 inches below the soil surface).

Peonies that are still immature. If your peonies were new two years ago or had been divided the fall before.

Competition - either from old, crowded peony plants that have weakened themselves or from nearby trees or shrubs whose roots are sharing that same soil.

Too much shade. That "good amount of sun" that you mentioned should be at least seven hours of direct sun per day in order to get flowers.

Lack of sufficient nutrients in that soil. While it is true that peonies do not need annual fertilization, a very poor soil; a sandy soil that won't hold nutrients; or soil where the nutrients go to other trees, shrubs or ground covers can cause peonies to form buds that won't develop.

Ants seem to love peonies because of the moisture that the plants hold. Usually, ants by themselves don't harm peonies. Ants are sometimes found where aphids are sucking fluids from plants, so look at your peonies for small, pear-shaped aphids. Aphids on ornamentals can be controlled with malathion, diazinon, insecticidal soap or the organic products Rotenone and/or Pyrethrums.

Q: I was wondering if you could tell us what can cause a cherry tree to bleed at the trunk. Also, the cherries won't develop on our tree. The sap runs out all the time. W.W.

A: Cherry trees will lose sap, which often seems to be thick, from any openings in the trunk or limbs. Your tree may have a physical problem, or those openings may be the result of borers if parts of the tree have wilted and died. Without further information, I cannot connect the openings, which allow the cherry's sap to continually flow, to its failure to develop a crop.

If you have a sweet cherry tree without a different sweet cherry variety nearby to pollinate the blooms, you'll get blooms but few or no cherries. An exchange of information would be required to properly diagnose this problem.

I am unable to list the address and phone number of your local Cooperative Extension office since your letter did not give your town. So, look in your local phone listings for the number of your extension office.

Send short questions about your lawn, garden, plants or insects to Dear John, c/o the Roanoke Times & World-News, P.O. Box 2491, Roanoke 24010-2491. We need your mail, but this column can't reply to all letters. Those of wide appeal will be answered each week.

John Arbogast is the agricultural extension agent for Roanoke.

by CNB