ROANOKE TIMES

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

DATE: SUNDAY, July 22, 1990                   TAG: 9007230316
SECTION: HOMES                    PAGE: E-1   EDITION: METRO 
SOURCE: John Arbogast
DATELINE:                                 LENGTH: Medium


PLANT EXPERTS NEED SAMPLES

Q: I have 28 white spruce trees lining my driveway. They are about 4 feet high. Some of the needles have begun to turn brown, and they look like they are dying. I have put acidic fertilizer around them this spring and mulched. I need information on how to care for them. A.V.S., Christiansburg

A: There are several possible causes for the browning of your spruces. Winter injury occurred in our region on certain evergreen varieties and might be the cause if the browning started in the spring. If that happened, there is not much that can be done other than pruning out damaged portions. If the trees were transplanted within the last two years and have not established root growth much beyond that planting size, the browning may be the result of drought injury. The solution would be to soak the plants once a week. A third possibility is spider mites, tiny sucking pests that are active on evergreens in the spring when it becomes mild but not yet hot and again in the fall. Call the extension office that serves your community and arrange to bring them a sample of the problem. The Montgomery County office is in Christiansburg, telephone 382-5790.

Q: In early spring, 12 hardy ice plants were planted. They were growing very good until about three weeks ago when something just about wiped them out. Insect spray did not help, and now I'm trying a fungicide. Examination of the plants shows a cottonlike substance, about the size of a Q-tip, at four or five places on the plant, which is about 12 inches in diameter. Please help.R.H.K., Moneta

A: This is another question thatmight be solved by taking a sample to your extension office, which is the Bedford County office at 119 E. Main St. in Bedford, telephone 586-7675. The white things you noticed sound like mealybugs, which suck sap from plants. They can be controlled on outdoor plants with two or three repeated sprays (10-day interval) of malathion, diazinon or Orthene.

Q: When is the best time to trim a Southern magnolia and how much should you trim it? This is a large old tree and it is hanging on the roof of the garage. Mrs. F.W.W., Christiansburg

A: The best time to prune a Southern magnolia would be in late winter or very early spring. However, if the pruning job you have in mind is to remove some lower limbs that are on a roof it would be OK to completely prune out those limbs now. Don't delay this project, since tree pruning is not advisable late in the growing season when plants are getting ready for dormancy. Remove no more than one third of the total leaf bearing parts of the tree at one time.

Q: I have five boxwoods along my walk that I have had for years. They are about 4 feet tall and have rounded out nicely. However, the last couple of years, they began to turn dark on one side. Part of them are completely dead on one side. Should I cut the dead part? If I do, the boxwoods will have a terrible shape. Mrs. E.R.H., Salem

A: Since the problem is only on one side, I would suspect a cause related to the environment (includes weather conditions) or site around the boxwoods rather than a disease or a pest. I hate to keep sending people to their extension offices with samples, but sometimes that is the only way a solution can be found. You are served by the Roanoke County office, located near the Salem Civic Center, telephone 387-6113.



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