ASK THE GARDENERS. Questions & Answers.

Q How much truth is there to the rumor that having a gas range is harmful to houseplants? We are building a new home, and plants will be an integral part of the interior design. Does evidence suggest it would be better for us to install an electric range instead of gas? B.K. Plymouth, Mich. Many people who heat or cook with gas can grow houseplants without any problem.

Evidence proves, however, that unburned fumes of either natural gas or propane can damage plants, whether they are in a home setting or a commercial greenhouse. An amount as small as one part gas in 100,000 parts of air is enough to damage certain plants.

The symptoms are curling of leaves due to faster growth of tissue on the upper side of the leaves' petioles. This gas-caused injury is known as epinasty. We experienced this recently in our gas-heated greenhouse, but have had no such problems with the gas boiler heating our home.

Tomato and marigold plants are sometimes used as test plants by commercial growers. These plants respond to gas in amounts as small as one part per million, thus alerting growers to a potential problem. Q Would you please give me the botanical name of lipstick plants? I was just given a beautiful one and want to look up care for it in a rather complete houseplant book which I have had for some time. Only rarely does it list common names, however. I was told it is in the African violet family, but it doesn't look like it. K.C. Boulder, Colo.

African violet and lipstick plant are both gesneriads (Gesneriaceae family). African violet is Saintpaulia and lipstick is Aeschynanthus. They take much the same care.

If you have a question about your garden, inside or out, send it, along with a self-addressed, stamped envelope, to the Garden Page, The Christian Science Monitor, One Norway St., Boston, MA 02115.

Doc and Katy Abraham are nationally known horticulturists.