I soak mine in warm water with root tone for 24 hrs. Then plant in a take-home container. The ones with black bottom with clear plastic tops. Makes a mini green hosue. Using sandy soil mix. Keep damp not wet. Covered. In two weeks then you can start to leave to top slightly open. When 3" tall, transplant into a gritty fast draining mix in there own pots. This method works for almost all cactus & Succulents.
First you have to make sure they are ripe and cleaned and dried. The berries can contain up to 3 seeds each.
