I have some outside in Scottsdale, AZ. I let the winter rains water them, and water maybe 3 times during the hot summer and they all bloom and are happy. They don't need much water, for sure. When we planted them in the ground, we dug out our clay soil and amended it with a cactus type mix with extra pumice and perlite. Even when we get flooding rains, the cactus are happy.