Plant in spring, choosing a sunny location. Bury nearly 2/3 of the plant. Tomatillos grow very well in pots, usually around 5-gallons in size for each plant. The soil will dry out faster than your garden soil. Water them every other day or more often in dry weather. The Tomatillo is of the nightshade family, bearing small, spherical and green or green-purple fruit of the same name. They are grown as annuals throughout the Western Hemisphere.