Most people are better acquainted with desert or arid climate cacti, which enjoy hot, dry conditions and are typically grown for their elaborate or unusual shapes. Cacti that are grown for their flowers, however, are actually rain forest cacti. These cacti need more moisture, less heat and less sunlight than desert cacti in order to thrive. Rain forest flowering cacti are easy to care for and are grown indoors in most regions.
Pot your flowering cactus in a sturdy container that has drainage holes in the bottom. Plant the cactus in a well-draining potting mixture containing organic matter, such as a mixture of two parts peat moss, one part sand and one part garden soil.
Position your flowering cactus in bright, indirect or filtered sunlight. Keep the cactus away from direct sunlight to prevent sunburn of the foliage and flowers.
Water your flowering cactus one to three times per week during the spring and summer, providing water until it begins to drain from the bottom of the pot. Don't let the potting mix dry out completely in spring and summer, but also don't keep the soil waterlogged or soggy. You should water the flowering cactus when the topmost layer of potting mix begins to dry out.
Feed your flowering cactus once every month while it's actively growing with a 10-10-10 NPK formula liquid houseplant fertilizer. Follow the dosage instructions on the fertilizer label and apply the fertilizer during watering.
Mist your flowering cactus daily with warm water to keep relative humidity levels at 50 percent or higher. If the flowering cactus's flower buds begin to drop before flowering, the air humidity is likely too low and temperatures are too high.