How to Grow and Cook Tomatillos: You Can't Do Mexican Without Them

Tomatillos (Physalis ixocarpa) are also called "ground cherry", or "husk tomato". They are a distant relative of the tomato, with a similar flower and fruit, except that the fruit is protected by a papery husk. The most common variety is the green-fruited one that becomes yellow, but occasionally you may see a variety that turns purple when ripe. These plants are essential for Mexican cooking, and a nice addition to many other recipes. They are used raw or cooked.

Growing tomatillos is easy. They will thrive in the average vegetable garden, and are easy to start from seed. They need full sun even in Arizona, well-drained soil, regular water, and some fertilization. If nurseries in your region don't sell them as started plants, seeds are available on the Internet. You must have at least two plants before they will set fruit. I always plant two or three of them because I want lots of tomatillos. They are frost-tender, but can even be grown in the long Alaskan summers with a bit of protection.

The plant is a sprawler. In Mexico they grow in the cornfields, spreading between the rows and along the fences. I use a tomato cage to try to keep the fruit off the ground and away from the quail. My experience last year was that by mid-July they had outgrown the support and the sprawling branches were firmly rooted into the ground at some of the leaf nodes. By late September my three plants were almost filling an 8 by 6-foot raised bed and overflowing a couple of feet on either side of the bed. Keep this in mind - tomatillos can overwhelm slower-growing plants.

It is not easy to tell when tomatillos are ready to harvest because you can't see inside the husks. Size is not a clue because the mature size can be grape to golf ball size. Fortunately, they are edible at any stage. They start out tart, like a green apple, and get sweeter as they grown and ripen. The best ripeness for most recipes is a light apple green, but don't worry if you find a pale yellow one. It's still good eating. I gently squeeze the husk to see how large the fruit is. If the fruit almost fills the husk, or is splitting the husk, it's ready to use.

I have not noticed many pests attacking the tomatillos, except for the quail that peck open any fruit that splits the husk or an occasional caterpillar that eats the leaves. I discard fruit with holes in it because crawly things lurk inside them. Birds will eat the fruits and seeds if they fall from the plant. Don't be surprised if your compost heap, corn patch, or flowerbed sprouts tomatillos. I dug up a dozen seedlings for co-workers this spring where fallen fruits had been.

Storing Fresh Tomatillos

The fruit lasts a couple of weeks in the refrigerator if you leave it in the husk and just refrigerate it. When you are ready to start cooking, remove the papery husk and wash the sticky sap off the fruit with cold water.

Freezing Tomatillos

I remove the husks, wash the sticky stuff off, put them in zip-close freezer bags and and freeze the tomatillos whole for later use in sauces and stews

To make a sauce base for freezing, simmer the husked and washed tomatillos in a small amount of water (with chilis, onions and garlic if you like) until they start to pop open. Puree and freeze this mix. Thaw it and add the cilantro and spices for your salsa.

Tomatillo Recipes

Fresh Tomatillo Salsa: This is the classic Mexican salsa verde and it's easiest thing in the world. Just throw fresh cilantro, chopped garlic, green chilis (preferably serranos, but jalapeños will do, onion chunks, and tomatillos into a food processor. Run the processor until it's as smooth or chunky as you want.

Use whatever proportions you want: I usually use equal proportions of tomatillos and onions, with what most people would consider far too much garlic and cilantro, and enough serranos to add a bit of heat.

It is a good chip dip. If you have leftover grilled chicken or fish, stir chunks of the leftovers into the salsa and it's instant salad or sandwich filling. It is also used mixed with cooked shrimp to make shrimp cocktails.

Grilled Tomatillo Salsa: Again, this is not chemistry. Use the proportions you prefer.

1. Husk and wash some tomatillos.
2. Put tomatillos, seeded green chilis, a couple cloves of garlic, and some big chunks of onion on a baking sheet or in a big shallow baking dish.
3. Broil for about 5 minutes, turn the stuff over and broil some more. The ingredients should start to brown and get soft.
4. Dump the broiled stuff into a food processor with some fresh cilantro, salt, and lime juice.
5. Run the processor until it's as smooth or chunky as you want.
6. Chill it if you want to.
7. Add salt if you want to.

This is a good dip for chips, or you can serve it with grilled fish or chicken as a salsa on the side. I often pour the salsa over chicken or fish and bake it.

• If you hate cilantro, or don't have any, you can substitute fresh basil and call it "tomatillo pesto". It's trendy.
• If you want the sauce to look greener, add a few fresh romaine or spinach leaves, They add color without changing the taste.

Other Recipes: When you have a vegetable producing as prolifically as tomatillos, you have to experiment with ways to use them. I tried tomatillos in the popular "slow-roasted tomato" recipe. It was delicious. I slice raw ones and add them to salads. I use them stews or vegetable soups.