Teryl Hirtz, Takoma Park: How do I divide a solid green Dracaena which had two separate plants growing out of the same single stalk? My Dieffenbachia has produced several suckers; should I attempt to separate them, leaving roots intact, or cut them on the stem and water root them?

I have a croton which had shot up a separate plant from the top. How do I remove this section for potting?

A. You can divide your Dracaena just about any way you want to. Cut off one or both plants and root them in a 50-50 mixture of peat moss and clean sand. Moisten the medium but do not make it soggy; place it in a pot and set the plant in it; firm the medium around the stalk and put a stake beside it; set the pot in a plastic bag large enough to enclose the whole plant, and close the bag by tying it to the top of the stake so the bag will not collapse on the plant. Keep the whole thing warm but out of direct sunlight. When new growth becomes apparent, open the bag a little while each day to accustom the plant gradually to conditions outside the enclosure.

You can test for rooting by giving a gentle tug; resistance to your pull indicates that roots have formed. When there are roots, the plant can be potted in its permanent container in a well-drained potting soil.

The stalk of the original plant from which you have cut plants will sent out new shoots if you continue to water and care for it as usual.

Fortunately for indoor gardeners, Dieffenbachia roots very easily from cuttings. Tips of tall canes can be cut off and rooted in damp sand or water, then transferred to pots of ordinary potting soil. When heavy stems are cut to within an inch or two of the soil, strong new shoots will emerge from the stubs in the pot.

If I understand you correctly, the suckers on your plant may already have roots; there should be no problem in severing them and potting them. If they are not rooted, cut them off and root them as directed from Dracaena. The stub of the Dieffenbachia will sprout new shoots below the cut.

You can cut off the top of the croton and root it in a manner similar to that outlined for the Dracaena. Or you can air layer the top. For a simple air layer, make a cut about one quarter inch deep in the stem, angling it upward; use a sharp knife or razor blade. Put a toothpick in the cut to hold it open. Surround the cut with a handful of wet long-grain sphagnum and wrap it in a piece of plastic; tie or tape the plastic at top and bottom so that the moss will remain damp. Roots will grow from the cut area; when they can be seen in the moss it is time to remove the wrap, cut off the rooted layer and plant it in a well-drained potting mix.

Eleanor G. May, North Garden, Va.: How do you prune night blooming cereus? Mine has leaves at the base and a long stem with leaves at the end.

A. You can cut back as much of the plant as you want. I would suggest cutting the long stem, especially if it is making the plant ungainly or top-heavy. Try to get the "heel" where the stem joins the rest of the plant if you would like to try propagating the cereus. For propagation, cuttings are usually a foot or so long. Set in clean sand, kept moist, the cutting should soon take root. Hyocereus will root in water also.

Walter E. Szuminski, Fairfax; My Aechmea fasciata kept sending out shoots after blooming, which I removed from the main plant, started out in other pots and now have six plants. Will the transplants ever bloom? How long does it take? Does putting the cutting in a plastic bag with a decaying apple force the plant to bloom?

A. Bromeliad authority Victoria Padilla reports that under optimum growing conditions Aechmea will bloom in three years from seed. It will put out a flowering spike two years after being severed from the mother plant as an offshoot. If a mature plant seems averse to blossoming, it sometimes can be induced to do so by changing its position, giving it more light, supplying more heat, or applying heavier feedings.

All mature plants will flower eventually. Indoor gardeners can turn the bromeliad into a bright-colored floral display with a ripe apple and a plastic bag, according to Dr. Henry M. Cathey, chief of Florist and Nursery Crops Research at the U.S. Department of Agriculture. Simply put the plant in the bag, add the ripe apple, close and tie the bag and leave it alone for four days. Then remove the bag and the apple and take care of the plant as usual. In one to six months, depending on the species, the plant will produce blooms.

Certain chemicals are at used times by commercial producers to stimulate the blooming process.

Indoor gardening questions may be addressed to Jane Steffey at The Washington Post, 1150 15th St. NW, Washington D.C., 20071. Please include your address and telephone number.