Q I want to use a large plastic bag to make compost of weeds, grass, and leaves, but I won't be home during winter to periodically untie the bag. If I leave the bag untied, will enough moisture get into the bag to decompose the refuse? N. C. P. Portland, Ore. No reason why you can't moisten the bagful of debris, add some soil and liquid fertilizer, and tie the top shut, then leave it all winter to decompose while you are away. It's easier to fill the bag if it lines a garbage can. Place a scoop of soil in bottom of bag, and for every 2 feet of refuse, throw in another shovel of garden soil. Moisten the whole mixture with a gallon of water (if it's a 25- to 30-gallon trash bag) and about a pint of liquid plant food. Store in the garage all winter and by
springtime you will have a bag full of ``black gold'' for your garden. In areas where temperatures frequently fall below 10 degrees F., the bagful won't break down as fast, unless you move it to a warmer spot. Q A friend has just given us several used clay pots. We want to sterilize them. How long should we boil them, or is there a chemical that could be used for this? There is a whitish material on some of them. A. M. Atlanta
The whitish material is from fertilizer and hard-water salts. A wire brush will usually get it off after the pots have been soaked. A solution of 9 parts water to 1 of household bleach is a good disinfectant. Heat the water to boiling, add the pots, then pour in the bleach and let stand overnight. We usually add a little dishwashing detergent to help loosen the salts. Incidentally, if there are any new pots among them, let them stand overnight in plain water. This helps fill up some of the pores. If not soaked, they will absorb water from the soil so quickly that the plants will suffer from lack of moisture. Plants in clay pots must be watered about twice as often as those in plastic pots. Q How do you preserve gourds? Last year we painted them with shellac, but they didn't keep well. C. S. R. Columbus, Ohio
Be sure gourds are mature before they're cut from the vines. Indications of maturity are deeper color and toughened stems. Leave gourds on vines until frost threatens, then cut them, leaving two or three inches of the stem. It'll fall off as it dries. Wipe gourds with a cloth dampened in a mild solution of household bleach and detergent. Let them dry two weeks in a warm dry place. We use a coat of floor wax on gourds, and buff with a soft brush. Some folks prefer the shine of shellac. Q I bought a hanging-basket plant at a garage sale. The attendant called it ``string-of-hearts'' but didn't know its name. It has small, leathery, heart-shaped leaves with beadlike growths. Can you enlighten me? C. M. Battle Creek, Mich.
The botanical name is Ceropegia (pronounced sir-oh-pee-gee-uh) Woodii (wood-e-i). A popular common name is Rosary vine; the beadlike bulbils can be used to start new plants. They can also be started from cuttings. The plant can be grown in sun, but ours prefers sunlight filtered through a curtain. It needs good drainage, and a good soil mix is 1 part each of loam, sphagnum peat moss, and perlite or sharp sand.
Ideal temperatures range from 72 degrees F. in the day to 60 degrees F. at night, but in summer the plant tolerates higher day temperatures, and in winter it can take 55 degrees nights. Q My mother had a ``snake plant'' with long, straplike leaves with horizontal dark stripes. Hers bloomed every winter, with tiny, fragrant star-shaped flowers. I have the same plant but no blooms. What can I do? V. G. E. Eureka, Calif.
Sansevierias are probably the easiest houseplants to grow, tolerating everything but a soggy soil. But if they are given regular watering so soil doesn't get parched in between, and the temperature stays about 72 degrees F. during the day and 65 degrees at night, and it gets a liquid feeding two or three times a year, it will usually bloom. They will grow in shade, but they get gangly. Sun is needed for blooming. Some of the cultivars now being produced are more attractive than the old-fashioned o nes, but they do not bloom as readily. Ours is like the one you describe. We keep it slightly pot-bound, and it blooms once a year.
If you have a question about your garden, inside or out, send it to the Garden Page, The Christian Science Monitor, One Norway Street, Boston, Mass. 02115. Doc and Katy Abraham are nationally known horticulturists.