Rio Grande Verde
Tomatillo in the US

Tomatillos are from the same family as tomatoes and eggplants, the Solanaceae, and they like it warm. You don't find plug plants for these much, so you'll be starting them yourself. Sow seeds indoors about 6 to 8 weeks before your last frost date. Plant them a quarter-inch deep in good seed-starting mix. Keep them somewhere warm, 70-80°F (21-27°C) is ideal, until they sprout. For zones with a longer growing season, like zone 8 or 9, you can start earlier, even February or January, and keep sowing right through spring for a continuous harvest.

Once your seedlings have a couple of true leaves, prick them out into individual pots. Give them a bit of space, they'll grow quickly. When all danger of frost is gone and the soil has warmed up proper, you can start hardening them off. Gradually get them used to the outdoors over a week or two. Plant them out about 2 to 3 feet apart. They can get quite tall and bushy, so a sturdy stake or a tomato cage will help keep them upright.