You should also be following our Succulent City Youtube Channel! Cactus cultivation is all about patience. However, it requires a steady hand and being attentive to any potential problems. Things can get a little more complicated when you grow your barrel cactus outside. You should use a balanced fertilizer every other month if the plant's growth is ongoing. If the plant was kept indoors, it is better for it to be outdoors in order to receive enough sunlight. The plants will be more comfortable being outdoors once they have been used to indoor life.