It is not too early to plant indoors seeds of lettuce, cabbage and onion, for setting them outside at a later warmer date.

Get your packets of peas ready. As long as the ground is soft enough for the spade, it is not reckless to sow peas among patches of snow. Some hardy gardeners believe you can never be too early starting your peas.

When it comes to dramatically improved new varieties, 1983 promises to be a great year for strawberry growers.

Unfortunately, however, you may run into problems in placing your order for the two most praised varieties. Called Tristar and Tribute, these ever-bearing strawberries are in the market in limited quantities for the first time this year. They are not listed in most catalogues, and only a few nurseries carry them.

Tristar and Tribute were developed at the Beltsville Agricultural Research Center, in cooperation with the University of Maryland, and are thus particularly well adapted to the Washington metropolitan area. Neither institution offers them for sale.

The first important advantage is that they bear fruit every six weeks instead of once a year. The new varieties, the result of 15 years of research, are called "daylength neutral" because they do not stop producing when the shortness of the day signals most strawberries to stop blooming.

Second, according to berry specialist Arlen Draper and Gene Galletta, Tristar and Tribute are the first everbearing varieties that are resistant to several diseases; red stele root rot, vernficillium wilt, leaf scorch and powdery mildew.

"The high quality fruit of Tristar and Tribute, along with their disease resistance and high productivity, make these plants a good choice for home gardeners and commercial growers," Draper said.

Tristar was enthusiastically endorsed by "Gardens for All," the handsome, practical monthly newsmagazine published by the National Association for Gardening, a nonprofit organization based in Burlington, Vt. The magazine quotes a grower, Prof. Elwyn Meader: "This is a real everbearing strawberry, not justg a two-crop-in-one-season berry . . . They are tough-skinned, too." The editors found Meader's Tristar berries "delicious, full of flavor with a gentle tang" and suggested that gardeners' follow Meader's recommendation for a screen of some type to keep off bugs and birds.

Another Beltsville-developed strawberry this year is name Allstar, with a fruit Galletta calls "mild and sweet, symmetrical and shapely, firm and full-colored."

Galletta called Allstar superior in "productivity, taste and size," and added that it was "dependable" and "specific to this area."

Allstar bears fruit in June and is resistant to the same list of diseases as Tristar and Tribute. According to Galletta, it can be planted in the spring or the summer and grown for pick-your-own farms and home gardens, for freezing and commercial production. Most important, Allstar is said to be available in many nurseries.

Allstar plant will become more readily available later this year, but not Tristar and Tribute. One reason for low supplies this year is that "Tristar and Tibute don't make runners readily," Galletta said. "And they don't come true from seeds."

A breakthrough in growing strawberries from seeds is claimed by Stokes Seeds Inc., 2043 Stokes Bldg., Buffalo, N.Y. 14204.

According to a statement from Stokes, the compnay's new variety called Sweetheart "allows the home gardener to grow from seed a strawberry that looks and tastes like a real strawberry."