Christmas cactus are succulents, not cacti. They need warm temperatures and bright light; after their holiday flowers fade, reduce the amount of water you give them. You can enjoy your potted Christmas cacti as a houseplant or move it outdoors in the spring, after all danger of frost has passed. Give it bright light, but not direct sun, and in some parts of the country, as the daylight hours naturally lengthen and then shorten again, new buds will form. Some gardeners may need to put their Christmas cacti into a completely dark location for 12 hours a day, for several weeks, in temperatures from about 50 to 55 degrees F., to stimulate new buds.