Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: SUNDAY, September 25, 1994 TAG: 9409270083
SECTION: HOMES PAGE: B-1 EDITION: METRO
SOURCE: John Arbogast
DATELINE: LENGTH: Long
A: R. Jay Stipes, extension plant pathologist for landscape trees at Virginia Tech, who also is known as "Virginia's Tree Doctor," said he has heard about this happening recently but that there really isn't an answer to why the oaks are dying. He likened it to a situation in which a physician simply doesn't know what's causing a person's illness.
Stipes did say that he knows of "nothing going around," such as an epidemic, that could be killing healthy oaks. Possible explanations, he said, include lightning strikes and accumulated weakening from years of summer droughts.
Q: I have several questions, but here are two: Should candytuft be cut back after blooming? Only the seed pods? How much? Also, why do some trees have sprouts growing around the base of the tree? How can this condition be prevented? A.P.A., Radford
A: Candytuft can be lightly cut back shortly after its spring bloom to cut off the newly formed seed pods. Of course, dead areas should be cut out whenever they occur.
Sprouts growing around the base of a shade tree usually are indicators that either the tree has been weakened, meaning that the old top growth cannot be maintained, and yet the roots are healthy and want to continue living; or the trunk has been injured by bumps, weather, pests or disease, thus causing the top growth above the injuries to die but the roots are strive to continue. Prevent this by avoiding those potential causes.
Q: Please suggest some low-maintenance, shade-loving ground covers for a steep hillside. Broad-leaf ivy is out, because it traps leaves and debris from our oak trees; and we'd like to avoid having to spread truckloads of mulch every year or so. There is some periwinkle along the edge, but it doesn't seem to want to spread down the hill. M.R., Covington
A: To support the growth and spreading of any landscaping ground cover, your steep bank must have decent soil (not shale or subsoil) and receive adequate moisture.
All your criteria should be met by pachysandra, which is also known as Japanese spurge. Your concern with ivy, that it can trap fallen leaves and debris, could be a problem with this choice also, but that hasn't been a problem in my pachysandra corner.
I'm sure you're aware that it will be necessary to do some watering until the plants are established. You should also spread mulch around any ground cover plants until they grow together and shade out weeds.
Take a long hard look at this bank to see what could be limiting that periwinkle before you invest a considerable amount of money or time in pachysandra.
Q: The yard of the home we recently moved to needs a great deal of attention. What would be the best way to get rid of (1) the rose of sharon that has grown up through the fence around the perimeter of the back yard so some flower beds can be installed and (2) some overgrown bushes in front of the house? Also, how do I prune an old rose bush with very old canes that measure 3-4 inches in diameter? I do not know what kind of rose it is, but it grows very tall. D.N., Roanoke
A: Eliminate all those unwanted bushes by cutting them to the ground. You'll have to dig out the majority of the roots left behind so you can plant something else.
Unfortunately, I can't suggest any shortcuts on that job.
Cutting them would keep most of the unwanted plants from rapidly sprouting back. However, if you want to leave roots in the ground, prevent sprouting by treating the freshly cut stumps of the rose of sharon (and all other leafy shrubs) with a brush killer labeled for "stump killing." Brush-B-Gon Brush Killer is a good example of this kind of product.
Needled evergreens generally don't regrow after cutting to the ground, so those stumps would not require treating.
In rose pruning, always cut out the dead or damaged parts first. Then do the rest. Since you wrote this letter back in mid-June, you've had a growing season to observe the flowering time and habit of that big rose. If your rose has bloomed continuously, treat it as an ever-bloomer and cut it back in the late winter or early spring.
However, if that big rose produced most if not all of its blooms during a period of only a few weeks, prune right after that period. If it grew this summer like a climber that was looking for something to grow on, provide a sturdy trellis adjacent to the plant and shorten the older shoots so they can be secured to that trellis with room for the season's growth to follow. If this might be a shrub rose with multiple trunks and fairly dense growth, prune by cutting the canes back by about half.
If your rose appears to be a neglected bush rose with just a few strong trunks and moderate summer growth produced, cut all those big canes back to about 30 inches at the appropriate time.
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. Personal replies cannot be given. Please don't send stamps, stamped envelopes, samples, or pictures.
John Arbogast is the agriculture and natural resources extension agent for Roanoke.
by CNB