I love growing tomatillos in containers. They are more forgiving than tomatoes--a bit more drought tolerant and disease resistant. I love watching them grow and change. It’s fascinating to see them transform from a bright yellow flower into what looks like a Chinese lantern, which houses the tomatillo fruit. You pick tomatillos when the husk is tight over the cherry tomato sized fruit, which should be firm but not hard as a rock. Some people also wait until the husk has gotten brown and papery or has split, revealing the green (or purple, depending on the variety) round fruit inside.
For more info on growing tomatillos