DATE: Sunday, August 24, 1997               TAG: 9708230043

SECTION: HOME                    PAGE: G3   EDITION: FINAL 

COLUMN: GARDENING

SOURCE: BY ROBERT STIFFLER, GARDENING COLUMNIST 

                                            LENGTH:  152 lines

MANDEVILLA BLOOMS IN HOT WEATHER

We purchased the mandevilla ``Alice du Pont'' in March. I transplanted it into a half barrel in late April. It seems to be doing fine as far as foliage goes, but at the end of May, it still had no buds or blooms. What information can you give me as to this vine?

I also have a river birch I planted 10 years ago. It is growing well, but it is always dropping twigs and small branches that almost seem to be cut off and not broken off. Is this normal?

Robert H. McVay, Norfolk

Mandevilla is a tropical vine and will not perform well until hot weather arrives. You'll recall we had a cold spring, with temperatures in the 50s as late as early June. With hot weather, it should bud and bloom. If you intend to try to overwinter it in your house, it's best to leave it in the pot. Otherwise, plant it in the ground.

As to your river birch, entomologist Peter Schultz, director of the Hampton Roads Research Center, says there is a twig girdler or limb girdler that attacks river birch. It is not wise to try and spray a tree that size. The solution is to pick up all the branches you find on the ground and destroy them. The girdler's eggs are in the branches you find gnawed off. By destroying them, you can prevent the insect from coming back to bother you and the tree next season.

We've read with interest the recent letters from readers who have black walnut trees and have to pick up after them. We have struggled with what to do with hundreds of walnuts that pelt our house, heads and garden every year.

We don't eat them and we're not willing to throw them away, so we give them away. We spend September and October collecting them daily and placing them in baskets and buckets in our front yard. We have a hand-lettered sign that reads ``Free black walnuts,'' and we provide a supply of grocery bags.

We have tentative and eager takers and even some regular customers whom we call every year. The messy, month-long task of picking up the walnuts is still ours, but there's a certain satisfaction in knowing that the nuts are not going to waste.

Loren and Paul Wilee,

645 Etheridge Road, Chesapeake

Thanks for an interesting letter. Black walnut afcionados now know where to go to get free nuts.

Have you ever seen or known of a Christmas cactus to produce a fruit or pod? The variety is Holiday Splendor. It produces a late red-purple bloom and then had three ``fruits'' approximately an inch long.

I've been around Christmas cactus most of my 72 years and have a porch full of several varieties ranging in color from nearly white through golden, pink, red and nearly purple. I never remember of any of them producing fruit or pods. I'm interested in knowing how and when to harvest and plant these pods. Will it be much like a prickly pear fruit or will it pop and spill it's seed?

I have some extra banana plants and have four that need good homes. They range in size from 6 inches to 4 feet. They are available for the best offers, sale or trade. This variety banana has produced fruit when the plant was 3 or 4 years old and gets to 15 feet tall.

You recently had an article on difficulty in growing gooseberries in this area. I bought three plants from Henry Field Nursery eight years ago. Two died within six months, but the third has thrived and produced more than I can use for years, although a late frost cut the 1997 spring crop. I think the variety is ``Welcome,'' but I'm not positive about the name.

Finally a strange plant came up in one of my flower pots a few months ago. It can best be described as a weed. The odd thing about it was if I touched it with bare skin I got an immediate stinging reaction. If not immediately washed, it would itch for days.

I pulled up the plant and tossed it in this week's trash before thinking to sketch it. It's definitely not poison ivy, oak or sumac. The leaves are 2 inches wide and 3 to 4 inches long, and the stems had a fuzzy appearance in a medium green color. One hand is still itching from contact with this strange plant.

Frank Pogue, Virginia Beach

(Call 464-6049 for bananas)

The plant that's stinging you is stinging nettle and you have aptly described what it does.

It's good to know gooseberries can be grown in this area, because gardeners who lived in more northern states would probably like to grow them.

You should get some calls on your banana offer although this time of year there's not much you can do with a banana tree except store it.

As to your Christmas cactus, a similar question was answered a few weeks ago. Bonnie Appleton says an insect or something pollinated some of your Christmas cactus, resulting in the seed pod you describe. Once the seed pods turn red, they are ready to pick. You can plant them in any good potting mix. Slightly cover the seed.

We planted certified Southern Belle grass in our new yard in 1995 and 1996. We put hay over it to keep the seed from washing away. I never raked the hay up after the grass started growing. The lawn looks green with very few weeds, except that the hay is growing. Is there a way to get rid of the hay other than pulling it out by hand? We have roughly an acre and quite a bit of hay is growing. We put down a pre-emergent in early March but that did not kill it.

Shell Riddle, Chesapeake

Horticulturist Laurie Smith at the Hampton Roads Research Center asks if you used hay or was it really wheat straw? That would be more logical, now that you're getting a lot of wheat (or something) coming up. She offers three options. Mow it close so it can't set seed. If it sets seed, it will reseed, and you'll have it year after year. Another is to buy or make a wick of Finale or Roundup. You can do this using a cotton glove, worn over a rubber glove. Dip the cotton glove in Roundup or Finale and wipe each blade of your ``hay.'' The last option, which apparently you're already doing, is to pull it out by hand.

Except on a steep slope, I've never used straw or hay when starting a new lawn. I think it creates more problems than it solves. Good luck.

About one year ago, you published a letter from a reader who gave a recipe for a marinade of Philippine origin that attracted earwigs by the dozen. I now am afflicted with earwigs all over my property. They eat my potted plants, bedding plants, roses, etc. My husband sprayed with Dursban this spring, but it did not do the job.

Would it be possible you might have this recipe in your files?

Lydia G. Wright, Virginia Beach

I don't recall publishing a recipe of Philippine origin to control earwigs. Entomologist Peter Schultz, director of the Hampton Roads Research Center, says earwigs do not usually eat plants. They eat rotten wood and other moist particles. He said that if you sprayed with Dursban, that should control them. A retreatment may be necessary.

An earwig looks like a cricket going backwards, with tail appendages that look like forceps. It is dark reddish brown, and they do all their roaming at night. Sevin, dusted around their hiding places, will control them. Try to clean up and eliminate all damp places where they might hide.

Are you sure the problem is earwigs? Could it be slugs? The damage you describe sounds like slug damage.

A weed or ground cover keeps popping up in my strawberry patch in the back of my 200-year-old house. Weed-B-Gon has not worked and neither has aggressive weeding. During the hot parts of the summer, this weed grows rapidly in a creeping vine-like manner and sprouts pretty little blue flowers for a couple of months. It fades in the severest cold. Can you identify it for me? A sample is enclosed.

It may help you to know that my soil is quite acidic, around 5.5 and is poor in nutrients. This is my second year in this house and this past spring, I began adding healthy, rich forest topsoil. I add bone meal, eggshells for calcium, 10-10-10, composted mushroom soil and cow manure. Do you think I am doing the right things for my environment or am I overcompensating.

I am still looking for one of your books close to my Pungo home. Any suggestions?

Kd King, Virginia Beach

Some gardeners admire the weed you have, although I'm not one of them. It's called Asiatic dayflower. When I grew up in Iowa, we called it wandering jew. It's proper name is Commelina diffusa. It's tough to eradicate. I pull and spray it every spring - and it still comes back.

Laurie Smith, horticulturist at the Hampton Roads Research Center, says to use Pro Roundup or Finale at the highest rate recommended.

As to your soil additives, it sounds like you're doing all the proper things. Next spring before you plant, take soil samples and have them tested. That will be a better gauge on what you should do for the future. 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. ILLUSTRATION: FILE PHOTO

Mandevilla is a showy tropical vine that produces beautiful blooms

in hot weather.

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