It's catalog times again!

A good productive garden begins with good seeds.

While some are available in bulk, most seeds come packaged in small envelopes (above) from display racks in garden centers, department stores, or even supermarkets. Too, the mail-order seed houses -- there are more than a hundred of them -- are another major source of supply.

Indeed, their products are promoted and often handsomely displayed in full-color catalogs. Vegetables, flowers, herbs -- you name it and they're all there.

While the seed packets themselves are printed on the back with basic cultural advice, the catalogs often go into even greater detail and are generally a good source of basic gardening information.

Maturity dates (how long from planting to harvest), insect and disease resistance, plant characteristics -- is it a bush or vine, short or tall? - color and taste characteristics, and whether it is an early-, mid-, or late- season variety.

Most of the seed houses supplying the home gardener will send out a catalog free for the asking. But be prepared for a lot of pleasant reading, and dreaming , around the fireplace in the North.

A few of those recognized for the quality production of their catalogs are: Burpee Seed Company, Warminster, Pa. 18991; Gurney Seeds, Yankton, S.D. 57079; Harris Seeds, Moreton Farm, Rochester, N.Y. 14624; Herbst Brothers, 1038 North Main St., Brewster, N.Y. 10509; J.W.Jung Seeds, P.O. Box 21, Randolph, Wis. 53956; and Geo. W. Park, P.O. Box 31, Greenwood, S.C. 29646.

For a free copy of ''Gardening by Mail: Where to Buy It,'' a booklet listing the members of the Mailorder Association of Nurserymen, send a stamped (40 cents), self-addressed, business-size envelope to MAN, Dept. MF, 210 Cartwright Blvd., Massapequa Park, NY 11762.

Give the catalogs a chance; you'll enjoy them.