The Christmas cactus is a unique type of cactus that thrives in a wide range of climates. It requires moderate amounts of light, but it also needs protection from direct sunlight. To ensure optimal growth, the Christmas cactus should be fertilized once every two weeks during the growing season. For the best results, use a liquid fertilizer that is high in nitrogen and phosphorus. Be sure to dilute the fertilizer before applying it to the soil, and avoid over-fertilizing as this can cause the plant to become weak or die.