Christmas cactus likes benign neglect

Before he left to settle in warmer, Southern climes, a neighbor of mine boasted a Christmas cactus that each year contributed as much joy and brightness to the festive scene as the lights on a nearby Christmas tree.

Moreover, this cactus bloomed spectacularly for many years because he knew how to coax it into flower.

''Treat the cactus a mite on the rough side come fall,'' he had been advised years before - and that's just what he did.

In short, he let the plant go thirsty and denied it any artificial light by putting it out with the cat on those nights when frost didn't threaten. Otherwise, the cactus spent the night in the closet.

If you bought a Christmas cactus last year and want a repeat performance from it this season, start right now to:

* Let the plant run dry. Water it only if you see it is beginning to droop.

* See that it receives no artificial light after sundown. As long as the temperature is not expected to drop below 40 degrees F., putting the plant out on the porch each evening is a good idea. Some people suggest that the temperature variation from warm day to cool night also helps trigger blooming, although this is nowhere near as important as withholding water and light. Remember, too, that frost will destroy the plant.

The drying period as well as the cool, no-lights-after-dark routine should last for about four weeks. When pinpoint buds appear at the tip of each leaf, bring the plant back indoors and resume watering. Half-strength liquid plant food applied every 10 days is a good idea at this time.

Flowering will begin sometime after Thanksgiving and continue into the New Year.

Christmas cactus plants, processed so that they are ready to begin blooming, will begin showing up in plant centers soon. Among them is a new patented yellow variety named Gold Charm.