Instructions: Years ago, before American tastes awoke to incoming ethnic cuisines and the attendant ingredients they required, "authentic" salsa recipes often called for green tomatoes.

But what we used to refer to as green tomatoes are, we now know, actually tomatillos - walnut-size, apple-crisp fruits encased in papery husks. They look like small tomatoes, but actually they are quite different.

The taste of a tomatillo is pearlike, with a slightly astringent undertone.

The texture is crunchy and firm, pleasant when eaten raw and still somewhat firm when cooked. In a salsa recipe, the play of fiery peppers, mild tomatoes and puckery lime juice so perfectly complements the sweet tomatillo that a sauce that includes them all will soar. (Occasionally, a recipe will specify that green tomatoes can be used as a substitute for tomatillos; thats poor advice.

It changes the entire flavor.)

Tomatillos have been showing up with increasing frequency at mainstream supermarkets; in many areas, the fruits regularly are stocked year-round. But even though theyre more widely available, they are well worth growing at home for the superior flavor that comes with freshly harvested specimens.

In the garden, tomatillo plants are quite unlike the sprawling, leafy tomato vine: The main feature is the fruit, which appears rapidly to fill in the sparse stems.

Tomatillos produce heavily. Husks hang like tiny Chinese lanterns all over the stems and branches of the plant. The green lanterns fill in gradually.

The harvest coincides with tomatoes and peppers, from August through early fall. Fruits are ready for picking when the husks change from green to buff or pale gold; fruits inside can be green, eggshell or lemon. There also is a purple variety, housed in green husks. All are similar in taste.

Twos company

Two plants would be plenty for the home gardener, for they are prolific.

Tomatillos are grown in the same conditions as all hot-weather annuals: full sun, compost-rich soil, plenty of water. They can go in as seedlings, but are fast-maturing enough to be sown directly in the soil at the same time as melons, squash and cucumbers.

Though they do not vine like cucumbers, the plants are sufficiently tall and flimsy to warrant support. They can be tied to a trellis as they grow or surrounded with a tomato cage. If left unsupported, tomatillo plants will bend and sprawl, depositing fruits on the ground, where they rot and leave behind myriad seeds to sprout this year and next.

In addition to support, tomatillos, like other summer crops, benefit from mulch. Black plastic is effective in keeping down weeds and retaining ground moisture.

Organic mulches such as grass clippings, shredded leaves, compost or shredded bark are all beneficial, too, adding nutrients to the soil, as well as retaining moisture.

Tomatillo plants are more common than they once were, though they are by no means ubiquitous.

www.johnnyseeds.com. The mail-order nursery carries three varieties - green, purple and an heirloom named De Milpa, which grows wild in the cornfields of Mexico. All varieties reseed abundantly, so once you have tomatillos in the garden, you should never have to buy plants or seeds again.

Plant some fine hot peppers, sweet tomatoes and a profusion of cilantro along with the tomatillos. The result this summer will be the finest salsa north of the border.

If you would like to email yourself the recipe for later use, or share the recipe with your friends or family, enter the email addresses below and this recipe will be emailed to you and others as well.