The Virginian-Pilot
                             THE VIRGINIAN-PILOT 
              Copyright (c) 1995, Landmark Communications, Inc.

DATE: Sunday, October 1, 1995                TAG: 9509290076
SECTION: HOME                     PAGE: G4   EDITION: FINAL 
COLUMN: GARDENING
SOURCE: ROBERT STIFFLER
                                             LENGTH: Long  :  162 lines

SEVERAL WAYS TO STOP OXALIS, IF YOU CHOOSE TO

Throughout the growing season, our garden is plagued with a weed that has been identified as Oxalis (wood sorrel). Some even say it is called shamrock. Can you comment on a control or remedy to rid the area of this pest? It has a bulb that is difficult to pull up, because the bulb breaks off.

John H. Peck, Norfolk

Virginia Tech authorities say there are several solutions. ``Make it uncomfortable,'' they say, by making sure it gets lots of sunlight, because it likes shade. In a lawn or garden, mulch it a lot and that will control or kill it. Finally, Roundup will kill it, but it may take several applications at the rate of 6 ounces per gallon of water.

Some folks like this plant and grow it as a flower. I agree with you that it's a nuisance, because it spreads quickly to take over an area.

I'm having a tough time this year with my peppers, tomatoes and beans. Also please tell me why anyone would put Epsom Salts by their tomato plants. I'll try anything to save my harvest.

J.P. Godsey, Virginia Beach

Epsom Salts are magnesium sulfate, recommended for peppers, tomatoes, grapes, daffodils, roses and African violets. Tomatoes and roses can use 1 tablespoon per month but on the other plants listed, use less. For more garden information on Epsom Salts, call (800) 600-2929.

I heard more complaints this summer than I ever remember on problems growing vegetables. My cucumber seeds would not come up; neither would my neighbor's. A good garden friend said, ``I can't get squash to grow for me anymore.''

It's unusual to have trouble with green beans, because they're one of the easiest vegetables to grow. Do you have rabbits? They'll eat off the sprouting plants, and you'll think the beans did not germinate. Rabbits will also eat the green beans before you get them picked. On the plus side, remember that for less than $50, backyard gardens yield about $175 worth of produce.

Early in May, my 12-foot, 7-year-old persimmon tree suddenly dropped 15 percent of its leaves. The tree looks very healthy as do the leaves, samples of which are enclosed. It is in bloom and should have its first crop of fruit this year. What could be my problem?

S.S. Nowak, Virginia Beach

Hampton Roads Research Center experts say the problem you describe is caused by loss of roots. It could be graft incompatibility, because nursery-grown persimmons are usually grafted trees. Mine died after five years of bearing fruit, because it got flooded once or twice each year with bay water. These trees can't stand too much water. It sounds as though yours has poor drainage or might be standing in water. If you can correct that problem, it should recover. I suggest you not try moving or digging much around it before cool fall weather.

I have a problem with my gardenia bush. I'm enclosing three leaves on which you can see black residue. Can you tell me what to treat it with? I lost a camellia last year with the same thing.

Recca S. Pepir,

Williamston, N.C.

Your gardenia has sooty mold, caused by whiteflies or aphids. On gardenias, it's usually whiteflies. If you find small swarming flies around the bush, they are whiteflies. Their excretion falls on leaves, and the fungus called sooty mold develops. For those not familiar with it, it looks like black chimney soot. Camellias also suffer from the same problem, though it is caused by scale insects on camellias. Spray weekly with Orthene to clean out the whiteflies. The sooty mold will then correct itself, but you can speed up the process by washing the plant with soapy water or insecticidal soap.

My question pertains to growing the herb basil. I start with strong plants that I put in planters and the garden. For the last two years, some of them suddenly wilt and die. I can't find evidence of insect damage, but the stems seem darkened at soil level. Does basil have a rot or fungus problem?

Jesse S. Hangen, Virginia Beach

Jeanne Pettersen, a member of the board of the Herb Society of America, says that recently many herb gardeners have had the problem you describe. There is a fungus that basil seems to be getting. There is no known cure except to rotate where you plant it each year, because the disease apparently is soil-borne. Pettersen says that purple basil seems to be more resistant, so you may want to try growing the purple variety next season.

We are getting ready to move to Fort Myers, Fla., on the southwest coast of that state. I have a tremendous number of bearded iris that I would like to take with me. Some are very expensive. I do not want to take them if they will not survive in that climate. I have been told by Florida neighbors that iris will not tolerate the climate but have not been able to find a nursery that can tell me for sure. Can iris be grown in that area? I am willing to do whatever it takes.

Linda P. Christoffersen,

Virginia Beach

Horticulturists at the Hampton Roads Research Center say that iris don't get enough cold weather in Florida for them to rest so they can bloom. They will grow but may not bloom. Unless you have everblooming varieties, it probably won't pay to move them from Virginia Beach to Florida. For more advice, I suggest you talk to probably the best iris growers in this country at Schreiner's Gardens in Oregon. Call them at (503) 393-3232, and they should be able to give specific advice.

I have two trees I need help with. The first is a Golden-rain tree. I planted it eight years ago, and it's now 15 feet tall. Leaves and bark are healthy, but the leaf growth is very sparse and it has not bloomed. The tree is planted where it receives full sun. I feed it each spring with McDonald special blend fertilizer. Is there anything I can to do to get the tree to bloom or did I plant a dud? The second tree is a 12-foot Ginkgo. It had a co-dominant leader that I removed three years ago and now the tree is growing crooked. The main leader is arching in the direction of where the second leader was trimmed, and it has a very bad S-shape to it. How can I correct that problem?

L. Poropatich, Virginia Beach

A Golden-rain tree needs a well drained location in full sun. Have you used weed and feed or sprayed your lawn with a weed killer around the tree? That could cause the problem. It's unfortunate, but many tree problems that readers write about are caused by using a weed killer near the tree. Golden-rain trees are normally healthy and bloom prolifically.

As to your Ginkgo, take a stake like a broom handle and tie the crooked leader to it. The new leader grew faster than normal when you cut out the other leader. It needs to be tied firmly to a strong but straight support and it will straighten up within a year or so.

What can I use to fill a hollowed out area in the trunk of a beech tree? The tree is probably 50 years old. The area affected is at the base of the tree, in a triangular shape. Can a non-harmful commercial product be used, in conjunction with an outer layer of tree dressing? Insects or animals are burrowing out the area and I want to fill it with something that will not harm the tree.

S.V. Hubbard Jr., Virginia Beach

Virginia Tech tree specialists say that beech trees are good at ``walling off'' such areas to prevent damage to the entire tree. It could be insects burrowing into the tree and then animals going after the insects. My suggestion would be to clean out the area with soapy water and a brush. Let it dry and then fill with urethane. It is sold in aerosol containers in home centers. After you fill the crevice, smooth it up and you can paint it to match the bark of the tree, if you choose.

I have a gardenia 4 feet by 3 feet growing on the northeast corner of my house. It has not bloomed for two years. Previously it had been laden with blossoms. I noticed around June 1 that my husband had pruned it back drastically. His reasoning was that it didn't bloom last year and it didn't have any buds this year, so he pruned it. I contended it was too early in the season to make that decision and to prune the bush to the extent he did. My neighbor has two huge gardenia bushes growing on the same side of her house as mine and they have bloomed profusely. They are never pruned and never get any attention.

Since my husband's retirement, he has devoted many hours to our lawn and borders. We have 190 azaleas, and in the spring it's breathtaking. We get lots of compliments on our yard, and we are proud of the results of his diligence. I will appreciate any comments you care to make with regards to his propensity for pruning!

Virginia L. Anderson, Portsmouth

The best pruning policy for gardenias is to leave them alone. Buds are formed on new growth. If the plant is so mature it doesn't put out new leaves, it probably needs pruning. New buds can be seen in late May, and the plant normally flowers in June. Gardenias seldom need pruning except to keep them to a desired size. Then it should be done immediately following after blooming.

I tend to be like your husband. I think you can seldom ``overprune,'' because it stimulates new growth, and most plants bounce back with vigorous new growth. With gardenias, however, leave them alone and they'll bloom best. MEMO: No gardening questions will be taken over the phone. Write to Robert

Stiffler, The Virginian-Pilot, 150 W. Brambleton Ave., Norfolk, Va.

23510. Answers will be published on a space-available basis. For an

earlier reply, send a self-addressed, stamped envelope. by CNB