Q This past summer I have had beautiful ornamental kale. It has lasted into the fall, but I am having trouble with cabbage worms. On my regular cabbage I merely handpick them, with good results, but the flowering kale is so crinkly that the tiny worms can hide. I cannot spot them until they have devoured large patches of the leaves. I do not want to use toxic materials. Is there any other way to get rid of the infestation? B.D.N.
St. Charles, Mo.
You can use a microbial pesticide called Bacillus thuringiensis directed specifically on the kale. You may find the material under Thuricide, BT, Di-pel, Bacthane, or Biotroe. The label will have the scientific name. It affects only the larvae of moths and butterflies; therefore it would kill the cabbage worms but not harm bees or other wildlife.
We sometimes hear concern about BT's killing endangered species of butterflies. Since the sulfur butterfly is the only Lepidoptera that lays its eggs on cole crops, it poses no harm to other members of this family, if you are careful to target your spray on the kale. Massive spraying of BT over large areas of wild and tame plants could kill desirable species. Massive spraying of conventional, non-selective pesticides eradicates beneficial insects as well as harmful ones. Bacillus thuringiensis is considered a selective pesticide, since it works only on Lepidoptera.
Q We enjoy your column, but we have never seen anything about carnivorous plants. We have heard that there are certain ones which can be grown as perennials outdoors, but we do not know which ones. We have sometimes purchased Venus flytraps in florist shops and grown them in a terrarium, and they always generate lots of curiosity from both adults and children. Could you recommend a good source of information and suggest a place that sells plants?
We seldom get questions on carniverous plants and we are glad to hear of your interest. They are fascinating, and every plant lover should grow at least a few at one time or another.
Fortunately, in our area we have a professional husband-and-wife team who have written an excellent book on the subject: ``Carniverous Plants of the World'' (Timberline Press). The authors, James and Patricia Pietropaolo, also have a mail-order business from which plants or their book can be ordered. Both they and their 27-year-old business have a fine reputation.
The book is large, has color photos and sketches, is full of good information, and includes other sources of supply. We have had the Pietropaolos show their plants on our television program. Both are science instructors. James teaches at a city high school and Patricia is an associate professor at a local community college. Their address is: Peter Paul's Nurseries, 4665 Chapin Rd., Canandaigua, NY 14424.