A number of years ago, my wife and I had the bright idea of growing potted herbs under glass in winter. We persuaded the produce buyer at Hannaford Brothers to market our plants in Shop ‘n Saves around Portland. The future looked bright until we ran into rather painful problems with production, as we discovered that some of the most popular herbs simply cannot be grown in a cool greenhouse during the short days of winter.

French tarragon, chives, dill and especially basil grew into such spindly, disreputable plants that we couldn’t bear to put our name on them and send them to market. The enterprise failed, and sadder but wiser, we set our sights on the much more certain market for pansies on Mother’s Day. In the meantime, herbal science has progressed splendidly, and I can now report that two of the above-mentioned herbs have been improved in ways that, had they been available earlier, might have saved our fledgling herb business.

Blue basil, sometimes called African basil, is an exciting addition to the family of culinary herbs. It is the result of a cross between African camphor basil (Ocimum kilmandscharicum), which grows 5 feet tall and is the commercial source for camphor, and the purple form of sweet basil (O. basilicum). Happily the hybrid possesses the vigor but not the pungency of the former and the flavor but not the wimpiness, for want of a better term, of the latter.

Whereas ordinary sweet basil produces weak, droopy foliage and almost no growth past the seedling stage in the winter greenhouse, but basil just chugs right along during the darkest days of the year. It grows to 2 1/2 feet, flowers mightily and very obligingly sends up a continuum of new growth. Ornamental value is superb as well, with long spikes of blue flowers reminiscent of the butterfly bush, Buddleya.

Judging by its vigor as a potted plant, I would expect that a single blue basil planted in rich garden soil early in the summer might produce as much useable foliage as two dozen ordinary sweet basil plants.

Being a hybrid, blue basil must be propagated by cuttings which, as with most members of the mint family, root readily in moist sand, perlite or sterile potting medium. Incidentally, the color is not at all blue, but rather an appealing blend of dark green and deep purple.

Our starter plant came from Logee’s Greenhouse (141 Nelson St., Danielson, Conn. 06239, catalog $3), the pre-eminent conservatory of exotic plants. Other specialty herb nurseries will doubtless begin to offer it soon.

French tarragon is a quirky little plant, much prized by chefs and gourmets. Its quirkiest quirks are that it rarely flowers, never sets seeds, and it drops into a profound dormancy in late fall, requiring either a chilling period or a long rest before resuming growth.

Only distantly related by virtue of belonging to the same gigantic family of plants (composites or daisies) is something called Mexican tarragon. The habit of growth is quite similar, and the flavor is virtually the same. But Mexican tarragon grows much more vigorously and is unaffected by short days excepting that, like many tropical plants, it flowers in winter. The flowers resemble tiny yellow zinnias.

I have not tried substituting Mexican for French tarragon in cooking, and can only presume by the evidence of my nose, that the effect would be acceptable to all but the most discriminating cooks. Our plant came from the west coast, a nursery called Goodwin Creek Gardens (P.O. Box 83, Williams, Ore. 97544, catalog $1).

Michael Zuck of Bangor is a horticulturist and the NEWS garden columnist. Send inquiries to him at 2106 Essex St., Bangor, Maine 04401.