Sorry to inform you, Stapelias don't grow straight up like yours. They will sooner or later fall along the ground and re-root and mine only booms on the stocks that are hanging down. When it's warm out, I put mine outside and let them have all the water they want. In full sun, they darken up to a more purplish color. Let it slowly get used to being in full sun. It may take weeks for it to get used to full sun.
