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For years I have had a double-flowered impatiens, which I have perpetuated from cuttings taken at the end of each summer. This summer's hot, dry weather apparently caused its demise. Friends also had similar luck with theirs. Would you have any idea where I could obtain another double impatiens? The one I had was pink. Fortunately plant breeders have now developed double impatiens that can be grown from seeds, and they were available for the first time in this year's seed catalogs. Double Duet is a bi-color, Double Rosette and Double Up are mixes of solid colors and bi-colors. We grew them this year and have found them prolific and stunning. They are not difficult to grow. Sow seeds on a moist medium, such as a mix of perlite, sphagnum peatmoss, and vermiculite and cover only slightly with just a dusting, as seeds germinate best when they have light on them. At a temperature of about 70 degrees F. they will take between 14 and 18 days to germinate. Keep medium moist.

I transplanted my aloe plant to a ceramic planter, and within a week it all turned mushy, except one little side shoot. What would have caused this? Aloe plants are very sensitive to overwatering. They need a well-drained soil and should be grown a bit on the dry side, in a container that lets air get to the roots. Ceramic containers are usually glazed, with no drainage holes, and water buildup drives out oxygen. Without oxygen, plant roots suffocate. Unglazed clay pots are best for succulent plants like aloe, as air can pass through the pores as well as drainage holes. If you have a side shoot that survived, set it on some moistened sand in a porous pot.

Would you help settle an argument? Do fireflies eat leaves of flowers and vegetables? We have seen them on our zinnias, and these plants are getting holes in the leaves. Also, what causes these insects to glow? We notice some of them are almost wingless. Fireflies are not considered pests of any crops. On the contrary, larvae and some other stages of lightning bugs eat snails, slugs, earthworms, and larvae of other insects. The larvae also produce a glow light. Males are the ones that fly , because the females are almost wingless. The flashing is to attract the opposite sex. The light is practically heatless, and the possibility of man's duplicating it has intrigued scientists for years. It is caused by the oxidation of luciferin in the presence of an enzyme called luciferase.

Last year, at holiday time, we noticed miniature pepper plants in florist shops. They were full of bright-red peppers. Some were thin and about two inches long, others were cone-shaped, and some were like cherries. Is it possible to raise these in our large bay window? It takes about five months for these ornamental peppers to bear after seeds are planted. They need a temperature of 70 to 80 degrees F. to germinate well, and planting medium must be kept moist. They would do fine if they got about 4 or 5 hours of sunlight a day. They are extremely attractive and are edible if you like 'em hot! You can order from most seed companies. Candlelight has pencil-thin peppers in clusters; Holiday Time has cone-shaped fruit; and Holiday Cheer has round, red fruit.

We have a small lilac that was started three years ago from a side shoot, or ''sucker'' of the parent bush. As yet, it has not bloomed. It looks healthy, but we're wondering if we should order one from the nursery. Do those started from suckers produce blooms? Your lilac will bloom eventually if it is in full sun. For years this was the only way lilacs were propagated. Nurseries still grow some lilac varieties this way. Lilacs need no fertilizer if grown in normal soil, but they need water during dry spells.

We have a potted five-foot ficus, or rubber plant. The problem is scale, which covers the leaves with a sticky substance. Can you suggest a remedy? Scale insects can be quite a problem on both indoor and outdoor plants. In your case, move the plant into a bathtub or someplace where you can drench the leaves and stems with the following solution, if the plant is covered with scale. (If you have only a few, you can wipe off each scale with a cotton ball dipped in the solution.) In 1 gallon of water, add 1 quart of rubbing alcohol; 1 tablespoon each of Tabasco sauce and liquid dishwashing detergent. If you drench the plant, wait 5 or 10 minutes, then wipe the scale off with a rag, doing it very thoroughly, making sure you have gotten them all. Pay special attention to stem and leaf joints. Adult insects have a waxy coat of armor that has to be dislodged; immature or crawler stage is vulnerable to conventional sprays, but it is difficult for the home gardener to detect. The above method will get all stages. Seal the rag with scale in a plastic bag before discarding.