Cacti can now be grown in teacups. Terrariums. Succulent birdbaths. Make sure you remove all dead stems and leaves from succulents' containers as soon possible. They do this through their stems, roots and leaves. A plant needs light to not only produce food but also to sustain itself. Overwatering can kill the cactus. Cactus are more susceptible to negative effects than those that receive too much light. The typical reasoning for root rot is overwatering. Overwatering is a common cause of rootrot.