Tomatoes are primarily an outdoor crop, but a few kinds can be grown indoors. Those grown outdoors are not suitable for growing indoors even in a greenhouse. Varieties are needed that yield well coupled with resistance to diseases that occur under greenhouse conditions.

Two good varieties for growing in the home during the winter are Burpee's Pixie Hybrid and Small Fry Hybrid. Seed may be available at some of the garden centers, or they can be ordered. Send for Burpee's free catalog, Burpee Seeds, Warminister, Pa. 18991.

Small Fry is an All-America winner, produces fruit early, small, tasty, bright red, marble shaped, one inch in diameter and of high quality.

Pixie produces bright scarlet fruit about 1 1/2 inches in diameter with a real big tomato flavor.

The big problem with growing tomatoes in late fall and early winter is inadequate light. Tomatoes need about 9 hours of sunlight daily to produce well. From late October through January, with many dull, sunless short days, there is not enough light for flowering and fruiting. The use of artificial light (fluorescent lamps are adequate) can solve this problem.

Studies by the Department of Agriculture Research Center, Beltsville, Md., suggest that fluorescent lights do an adequate job of producing healthy plants, and the cost is small.

Petunias grown under fluorescent lights looked like those grown under greenhouse conditions; they were compact and luxuriant, with deep green foliage.

According to Dr. Henry M. Cathey, chief of the USDA ornamentals laboratory, light from an incandescent source is in the red range, which promotes internode lengthening and eventually turns the plants into climbing vines.

Incandescent lights, such as hanging flood lamps can be used in decorative arrangements to supplement light from a window, he says, but good natural light must be available also.

Fluorescent lights, regardless of color, can be used to promote growth of most plants indoors.

Growing tomatoes in a greenhouse is quite different from growing them in the field, Cathey says. A variety is needed that yields well coupled with resistance to major diseases.

Rate of fertilization is important in greenhouse gardening, especially with nitrogen. With too much, the plants become overly vegetated and bear poor quality fruit.

With too little fertilizer, stunting occurs, especially if the nitrogen is applied toward the end of the season.

In many greenhouses, especially plastic ones, high humidity causes problems. Several plant diseases flourish so that disease resistance is greenhouse tomato varieties is of major importance.