DATE: Sunday, November 23, 1997             TAG: 9711220068

SECTION: HOME                    PAGE: G4   EDITION: FINAL 

COLUMN: GARDENING QUESTIONS

SOURCE: BY ROBERT STIFFLER, GARDENING COLUMNIST 

                                            LENGTH:  118 lines

POPLAR IS POPULAR, BUT ITS ROOTS MAKE IT A POOR CHOICE FOR YARD

When my husband and I moved back to this area several years ago, we bought a home in one of the many new subdivisions that were formerly farm fields. We had a flat, treeless yard in a flat, treeless neighborhood. In our rush to develop a lush lawn with trees, we foolishly planted poplar trees, because they were supposed to be fast growing. The ads were right - they grow and grow, almost overnight. But we found that they grow almost straight up and do not have a strong enough root system to withstand winds.

So after four years, we tried to remove them. We dug up what we thought were all the roots and believed that would be the end of the problem. Now we find that little poplars are coming up all over our yard. Please tell us how to eliminate the fast-growing poplar forest that wants to take over.

K. Jones, Virginia Beach

You've been misled like so many other homeowners with those misleading ads promoting poplars as good trees for your home. Virginia Tech tree specialist Bonnie Appleton says to paint the poplar sprouts with Roundup concentrate straight out of the bottle. Don't get the ready-to-use, diluted Roundup.

Another method would be to cut off each sprout at ground level and pour on the roots a small amount of Weed-B-Gon and motor oil mixed in equal proportions. Be sure to cover only the exposed root, because that mixture will kill anything it touches.

Enclosed is a piece of a bush I have. What is it and why is it dying? Can I do something to save it?

Josephine Williams, Chesapeake

The plant you sent is a juniper. It could be dying because its roots are too wet. Spider mites also can kill juniper or perhaps it has a fungus. The sample you sent had been dead so long that the culprit could not be identified.

Take a sample to the extension office in Chesapeake. The horticulturist should be able to tell you how to cure the problem.

Last July, you wrote a column that contained a formula for the control of mildew on crape myrtles and possibly dogwoods. Would you please repeat that information?

Mildred C. Callahan,

Virginia Beach

Tom Banko, plant disease specialist at the Hampton Roads Research Center, says these products are recommended to prevent or correct mildew on dogwoods and crape myrtle: Funginex, Immunex, Bayleton or Systane. Any or all should be available in most garden centers.

The organic spray recommended is 1 1/2 tablespoons of horticultural oil and 1 tablespoon baking soda in 1 gallon of water. Do not use on a hot day. Spray in the evening.

I would like info on planting the seeds of my clivia, including what position to place them in the soil, how to prepare the seeds and how long to expect for germination.

Dr. Norman G. Sedel,

Virginia Beach

Clivia or Kafir lilies are propagated in late spring by dividing the bulbs, according to most houseplant books. However, the book ``Parks Success With Seeds,'' by Ann Reilly says that seeds must be sown immediately, when they're ripe and fresh.

Plant deep enough to cover the rather large seed when planting. Maintain a temperature in the potting medium of 75 degrees during germination. It takes 30 days or more for them to germinate.

Clivia bloom more abundantly if their roots are not disturbed. Repot only when the plants become extremely overcrowded, which is usually every three or four years.

Reilly's book is the best on growing from seeds. It is now out of print and most likely can be found only where old books are sold.

This is the second year I've had calla or arum lily in my flower beds. One plant has solid green leaves and another has speckled leaves. When it blooms, the bloom will get very heavy and fall to the ground. It appears the bloom becomes a seed pod. What do I do with them?

Last year, it seems I planted one and this year I have a dense growth of short plants. The leaf enclosed is from a plant, and the flower looks similar to calla lily except the flower part appears to open inside out. I have a large clump of them and am thinking I need to separate the clump, because I got only one flower this past spring. Leaves are falling over and also seem to be heavy. Is it a calla lily or something else?

Cindy H. Bright, Virginia Beach

Your plant is Italian arum, a member of the arum family that includes calla lilies as well as many others. Some people call your plant ``wild ginger,'' because it has practically become a native in the South. The bloom is insignificant and the part of the plant gardeners enjoy is the spathe or seed stem, which forms after the bloom fades. Red berries cover the spike, which can be a foot tall. Birds love them and you often find the spike stripped.

They do spread all over your landscape, so you'll find arum in many places you did not expect or want it. It sounds like your clump is so thick it should be divided but be aware that over the next few years, you'll find it scattered everywhere. Flower arrangers like the plant for it's large green leaves, some of which are striped. They remain green almost all winter.

Can you please identify the plant enclosed? It appears along my border fence and has grown to about 8 feet high in the past two years. It has very fragrant flowers.

Beth LePine, Sandbridge

Your plant was identified by Curator Kunso Kim of the Norfolk Botanical Garden as privet. Most people consider it a weed. It grows in the wild and birds spread the seed. There are some good species that are evergreen and Kim commented that more people should grow it, because it is a tough plant.

It usually grows in the woods so I'm surprised it's growing in the sand at Sandbridge. Blooms have a pungent smell, and some folks don't like the odor. You can move it in the fall or winter to form a hedge, but it does shed its leaves most winters.

Will you please repeat the formula for a soil sterilant that contains vinegar, salt and soap?

Ann Mejias, Virginia Beach

Here's the formula, courtesy of the Green Thumb EXTRA:

In a 3-gallon bucket, combine the following: 1 gallon of 5 percent acidic vinegar; 1 pound table salt; 1 tablespoon liquid hand soap. Mix and dissolve the ingredients.

The best way to apply is to use a pressure tank sprayer. Spot-treat areas where weeds are growing. This organic weed killer is good to kill weeds in the cracks of driveways, in gravel driveways and pathways and other areas where weed growth is not desired for up to one year.

Caution: This is a temporary soil sterilant and will kill anything it touches, including roots. Do not use over the root zone of trees, shrubs, flowers, vegetables, the lawn or other plants you want to keep.

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