Christmas cactus (Schlumbergera truncata or Schlumbergera x buckleyi) is sometimes also known as Thanksgiving or holiday cactus. Hardy in U.S. Department of Agriculture plant hardiness zones 10 through 12, the tropical cactus is frequently grown indoors outside of its hardiness zone. The flowers, which can be brought into bloom in time for various winter holidays, may be red, purple, pink or white. In some varieties, the flowers are a combination of pink and white.
No matter what the flower color, Christmas cactus feature long, arching stems that are segmented and appear either round or flattened in cross section. The flowers are borne on the ends of the stems and feature rather irregular petals fused at the base of each flower to form a tube. This facilitates pollination, which is done by hummingbirds. Spines are either not present or are so weak as to be unnoticeable. Plant breeding has expanded the range of flower colors to include yellows as well as variations in traditional Christmas cactus colors.
In the Pink
One white Christmas cactus variety with pink in its color mix is "Gina" (Schlumbergera "Gina"). The pinkish-white pointed buds open to flowers featuring white petals flushed with pink towards the flowers' centers. The contrasting style is dark red. Another variety, "Bicolor," also features white petals combined with rose or pink. "Delicatus" (Schlumbergera truncata var. "Delicatus") also has white petals that age to pink, somtimes with a darker red ring around the throats of individual flowers.
Growing Christmas Cactus
White Christmas cactus and its colorful relatives all thrive under the same conditions: bright, indirect light, well-drained soil and watering only when the top of the soil feels dry. Root rot, caused by overwatering, is the number one cause of cactus and succulent death. Flowering is dependent on two factors, light and temperature. Keep temperatures between 70 and 80 degrees Fahrenheit. If temperatures rise above or drop below that level, when the plant is in bud, the buds will drop as well. Christmas cactus also requires at least 13 continuous hours of darkness per day for about eight weeks to stimulate flowering.
White Christmas cactus is an excellent greenhouse or windowsill subject, mingling with other white and pink flowered plants, such as African violets (Saintpaulia ionantha), generally hardy in USDA zones 11 through 12 and grown indoors elsewhere. Like other potted cactus species, Christmas cactus can spend warm weather months outdoors in a protected, shady spot. It can be displayed in groups of potted cactuses and succulents or positioned atop a pillar in a shady garden spot.
- The American Horticultural Society Encyclopedia of Plants and Flowers; Christopher Brickell, Editor-in-Chief
- Missouri Botanical Garden: Plant Finder -- Schlumbergera Truncata
- Hortus Third; Liberty Hyde Bailey, Ethel Zoe Bailey, et al.
- The Random House Book of Indoor and Greenhouse Plants, V 2; Roger Phllips and Martyn Rix
- Missouri Botanical Garden: Plant Finder -- Saintpaulia Ionantha
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