THE VIRGINIAN-PILOT
Copyright (c) 1994, Landmark Communications, Inc.
DATE: Sunday, September 11, 1994 TAG: 9409090100
SECTION: HOME PAGE: G2 EDITION: FINAL
COLUMN: GARDENING
SOURCE: ROBERT STIFFLER
LENGTH: Medium: 74 lines
I have several holly trees (Stevens, Burford, etc.) that are 10 to 15 years old. They all have white splotches on the undersides of the old leaves. Should I spray the leaves to control this disease? Is this harmful or just unattractive?
Stanley R. Purcell, Virginia Beach
Entomologists at the Hampton Roads Agricultural Research Center say you most likely have cottony scale and you are seeing their egg sacks. This scale is not harmful but certainly not attractive on holly leaves. If you want to eliminate the scale, spray around June 1 and again 10 days later with Orthene. An organic alternative is to spray with an insecticidal oil in early spring.
Enclosed is a limb from one of our boxwood plants. It is dry looking and deteriorating. Can you tell us what to do to bring this boxwood back to good health?
Cecile Slagle, Virginia Beach
Virginia Tech pathologists examined your boxwood and report it has no disease and no insects. There is a general boxwood ``decline'' throughout Virginia. Some suggestions that may help are: Water boxwood once a week (but don't overdo it). Test your soil. If the pH is too acid, boxwood responds to lime. Or it could be a root problem. They are heavy feeders, so fertilizer sometimes helps. If you fertilize now, use cottonseed meal, which is very gentle. Otherwise, fertilize in late winter with a shrub fertilizer. Also, keep fallen leaves picked out of the interior of the plant. You'll probably have to experiment before you get results.
Each spring we have aphids in our maple trees. They are so bad we're unable to leave laundry on the line or park our vehicles in the shade of the tree. Is there anything we can do to control them or rid the maples of this troublesome infestation? The trees are too tall for a spray to reach the higher foliage.
Burton E. Grizzard, Capron
It is unusual for maples to have aphids, say Virginia Tech entomolgists. Don't spray, because if the problem is aphids, they are a nuisance for only two to three weeks in the spring.
The experts believe you may have scale and the drippings are honeydew (excrement) from the scale. That can be a nuisance. You need to eradicate the scale in order to solve the problem. Call an arborist to get an on-the-spot inspection and recommendation.
I have two white dogwood trees facing the street that are several years old. Last year I noticed one had wilted leaves and several dead branches. This year both trees have the wilted leaves. Please tell me what is wrong and what I can do to save them.
Julia B. Hirsch, Norfolk
Have you used weed and feed fertilizer around them? That will damage the roots and cause the damage you describe. Whatever the cause, it sounds as if the roots are damaged.
Virginia Tech pathologists say they are baffled at some of the dogwood problems they're seeing. They've sent samples to the landscape maintenance lab in Blacksburg, and that clinic could not identify the cause. They know there is a problem but it is ``something new and different.'' When leaves die and drop, the stem will die. Always cut back such stems until you find green, live wood.
If bark on the trunk is not broken and the root system is healthy, the tree should not wilt. This has been a tough year for dogwoods. Once they lose their leaves this fall, fertilize them with tree food spikes or a special tree food and see if they don't look better next spring. MEMO: No gardening questions will be taken over the phone. Write to Robert
Stiffler, The Virginian-Pilot and The Ledger-Star, 150 W. Brambleton
Ave., Norfolk, Va. 23510. Answers will be published on a space-available
basis at the proper time for their use in the garden. For an earlier
reply, send a self-addressed, stamped envelope. by CNB