Holiday cactus is the collective name used to refer to a group of closely related flowering houseplants including Christmas cactus, Thanksgiving cactus, and Easter cactus. These easy-to-grow indoor plants can be very long-lived sometimes being passed down from generation to generation. The long life of these plants is due to the fact they are easy to grow. They thrive on benign neglect, have few insect and disease problems, and don’t require frequent repotting.
Holiday cacti are native to the humid, tropical and semi-tropical mountainous forests of southeastern Brazil. They are epiphytes which means they grow on and in the crotches of trees but are not parasitic. Plants derive water and nutrition from rain and decaying organic matter. The stems of holiday cacti are composed of flattened stem segments or phylloclades. The leaf-like phylloclades carry on photosynthesis for the plant and give the plant its unique appearance. The flowers on holiday cactus are formed on the tips of the phylloclades.
Several types of cacti are often referred to as holiday cacti. All of them are in the cactus family (Cactaceae) and in the genus Schlumbergera. They are similar in appearance but have distinctive characteristics.
The Thanksgiving cactus is probably the most familiar and widely grown species of holiday cactus. Botanically, it is Schlumbergera truncata but over the years it has been classified under other genera including, Epiphyllum truncatum and Zygocactus truncatus. Thanksgiving cacti are available from greenhouses and other retailers in early fall through the Christmas season. Flower colors range from white to red, lavender, and salmon-orange—with many shades of each. The stem segments of the Thanksgiving cactus bear 2-4 upward-pointing teeth. The flowering period is generally from mid-November to late December.
The true Christmas cactus, Schlumbergera × buckleyi is a hybrid between S. russelliana and S. truncata. It has also been classified under several different names in the past including, Epiphyllum buckleyi, E. rollissonii , and Schlumbergera bridgesii. This hybrid originated in England about 150 years ago. Most of the plants commercially available and sold as "Christmas cactus" are actually either the Thanksgiving cactus (S. truncata) or hybrid cultivars, not the true Christmas cactus. Plants have stem segments with scalloped edges and have no pointed teeth as with Thanksgiving cactus. The arching branches produce three-inch, rosy-red flowers from late November to early February.
Numerous cultivars of holiday cacti are grown. They differ in branching habit, rate of growth, shape of foliage segments and flowers, flower color, time of flowering, and plant habit (pendulous, semi-pendulous, or erect). The physical characteristics and bloom time of some cultivars most closely match those of the Thanksgiving cactus, while other cultivars more closely resemble the Christmas cactus. Some have an intermediate appearance.
Not nearly as common as the other types, the Easter cactus (Schlumbergera gaertneri) has had a number of former names including Hatiora gaertneri, Rhipsalidopsis gaertneri, Epiphyllopsis gaertneri, Rhipsalis gaertneri, and Epiphyllum russellianum - with so many former classifications it can be difficult to keep up! The Easter cactus differs from other holiday cacti primarily in its season of bloom. Plants bloom from March through May with pink or red flowers. It occasionally blooms again in early fall. The stem segments of Easter cacti are smoother than the other holiday cacti, with 4-6 slight ripples along their edges, and brownish hair-like bristles at their tips.
Carefully wrap holiday cacti when transporting them outdoors in winter. Exposure to cold temperatures may damage the plants or cause the flower buds to drop off.
Holiday cacti are not demanding plants. All three types require similar growing conditions. Indoors, holiday cacti prefer bright, indirect light and temperatures of 60 to 70°F. Grow in well-drained potting soil, but a special cactus mix is not required. All-purpose potting soil can be used if it drains well. Plants grow best when slightly pot-bound so only repot when plants completely outgrow the container. Holiday cacti can go many years without repotting. When needed, the best time to repot is spring or early summer when plants are not in bloom.
Despite being in the cactus family, holiday cacti do not want to be kept dry like their relatives. While in bud and flowering keep the soil evenly moist. If conditions dry out too much while in flower, the buds or flowers will drop off prematurely. After flowering, place plants in a slightly cooler area and water less frequently.
The plants should be kept on the dry side during the remainder of the winter. Water the plants more frequently during their active growth period from spring through summer but be sure to allow the soil to dry completely between waterings. Overly wet conditions will cause holiday cacti to develop limp growth and root rot. Fertilize holiday cacti approximately once a month during the growing season.
Required Conditions for Flowering
The flowering of holiday cacti is controlled by temperature and day length. Holiday cacti are short-day plants. Short-day plants grow vegetatively during the long days of summer and produce flowers when the day length becomes shorter in fall. Most species and hybrids need a day length of 12.5 to 14 hours or less to bloom. To get the best results, provide an uninterrupted dark period of 14 to 16 hours to initiate flower bud development.
Temperature also plays an important role in flower development. Temperatures above 70°F will prevent flower formation even if the days are short enough. To get bloom indoors temperatures between 60 and 70 °F must be provided along with a short day length. Some Christmas and Thanksgiving cacti will bloom if kept at 55°F in fall, regardless of day length.
How to Get Flowers in Your Home
To ensure flowering development, in late summer, place the Christmas cactus in a cool location (55 to 65°F) that receives bright light during the day, but no artificial light at night. For example, lights from a frequently used lamp or kitchen light can disrupt the day length and prevent bloom. An unused bedroom or basement may have the proper environmental conditions. Good, consistent care is especially important during flower bud development. Allowing plants to dry out too much, drafts, and excessive watering during flower formation may cause the buds to drop off the plants. Additionally, do not move the plant during flower bud development. The Christmas cactus can be moved and displayed in another room when the first flowers begin to open to avoid flower bud drop.
Flowering of Easter Cactus
Unlike the other types, Easter cactus has a more regimented temperature and light requirement to produce blooms. During the short days of fall plants require temperatures of 60-70°F for 3-4 weeks followed by temperatures of 47-55°F for 4-6 weeks. After this short day and cooling requirement have been met, plants should be grown under longer days in a room with a temperature of 60-70°F. This complicated series of day-length and temperature requirements can sometimes happen naturally through the winter months to allow for bloom in spring. However, if these conditions and timing are not met, the Easter cactus will not likely flower.
Holiday cacti are easy to propagate. Remove sections of the plant consisting of 2 to 5 flattened stem segments (phylloclades). Cut or pinch off each section at a joint. Allow the cut/pinched ends of the cuttings to callus overnight. The following day, fill a pot or other container with perlite or coarse sand. Water the rooting medium and let it drain for a few minutes.
Insert the cut/pinched end of each section about 1 inch deep into the perlite or coarse sand. Do not insert sections upside down. Firm the perlite or coarse sand around the sections to keep them upright. After all the cuttings are inserted, water the rooting medium again. Allow the perlite or sand to drain for a few minutes and then set the container in a brightly lit location.
Periodically examine the cuttings over the next several weeks and water the rooting medium when it begins to dry out. The cuttings should root in about 6 to 8 weeks. When the roots are one inch or longer, plant the cuttings in a pot using a well-drained potting mix.
Holiday cactus requires proper environmental conditions to flower. Critical factors in flower initiation are day length and temperature.
Holiday cacti are short-day plants. Short-day plants grow vegetatively during the long days of summer and produce flowers when days become shorter in fall. The Christmas cactus will not bloom properly if exposed to artificial light at night in the fall. This light can come from any source including lamps, kitchen lights, and even closeby streetlights. Plants must have 14 to 16 hours of uninterrupted darkness to bloom.
Flowers may also fail to develop if the plant is exposed to temperatures above 70°F. Night temperatures of 60 to 65°F with slightly warmer daytime temperatures are ideal for flower formation.
Flower Buds Fall Off
Any sudden change in environmental conditions can cause flower buds to drop off before opening. Provide good, consistent care during flower bud development. Avoid excessive watering, allowing the soil to dry out too much, or other marked changes to their care during flower bud development. To avoid flower bud drop, do not move the plant during flower bud development. Holiday cacti can be moved and displayed in another room when the first flowers begin to open.
Small Brown Bumps with a Sticky Substance On and Under the Plant
The holiday cactus may be infested with scale insects. These small insects are covered with scale or shell-like, waxy coverings. They attach themselves to stems or leaves and suck sap from plant tissue.
The life cycle of scale insects consists of the egg, nymph, and adult stages. Eggs are laid below the scale coverings of adult females. When the eggs hatch, the nymphs crawl from underneath their mother’s scale and move a short distance to their own feeding site. The newly emerged nymphs are also called crawlers. At their new locations, the nymphs insert their slender stylets (mouthparts) into the plant and begin sucking sap. The covering or shell develops soon after feeding begins. Scale insects remain at these feeding sites for the rest of their lives.
Scale insects are difficult to control. Systemic insecticides are generally ineffective. The shell-like covering protects scale from contact insecticides. Contact insecticides are only effective when applied during the crawler stage (before the insects develop their protective shells). Since it’s difficult to determine when crawlers are present, scale-infested plants will need to be sprayed with insecticidal soap every seven to 10 days until the infestation is eliminated. Small infestations can be controlled by individually scraping off the scales or by dabbing each scale with an alcohol-soaked cotton swab.