Start early for December blooms
The Christmas cactus, Schlumbergera bridgesii, is a beautiful plant belonging to the genus Schlumbergera, a small group of cacti found in the coastal mountain rainforests of southeastern Brazil. The Christmas cactus grows in crotches of trees or rocky crevices and is an epiphyte. It receives moisture from the rainforest’s damp air and daily rains and nutrients from leaf debris that accumulates in the trees’ crotches or in the rocky crevices where the plant lives.
Common names for Schlumbergera species refer to the seasons in which they bloom. The Christmas cactus (S. bridgesii) blooms in December, the Easter cactus (Rhipsalidopsis russelliana) blooms in April and the Thanksgiving cactus (S. truncate) blooms in November.
The Christmas cactus is a hybrid between a Schlumbergera truncate and a Schlumbergera russelliana. All three varieties look a bit different. The Christmas cactus has flattened branch segments with scalloped edges. The Thanksgiving cactus, Schlumberger truncate, has pointed “teeth” along its segments. The Easter cactus, Rhipsalidopsis gaertnerii, has pointed “teeth” along its segments and fibrous hairs growing from each jointed segment.
S. russelliana (Easter cactus) has white, red, orange, peach, lavender or pink blooms. S. truncate (Thanksgiving cactus) has blooms in shades of orange, red, peach or pink. S. bridgesii (Christmas cactus) has red or pink blooms.
In order to have a Christmas cactus bloom in December, you must place the plant in total darkness beginning in late October or early November so that it receives at least 12 hours of complete darkness daily for about four to six weeks with a temperature of 55-70 degrees. If the room’s temperature is above 70 degrees, the plant needs 15 hours total darkness. Water just enough to keep the soil moist and do not fertilize. These conditions mimic the plant’s winter environment in the Brazilian rainforest and allow the plant to rest before focusing its energy on producing blooms once it is brought out into the light in December.
Once the dormant period is finished, place the plant where it receives indirect sunlight and gradually resume regular watering. After its rest, buds will appear on the tips of its branches, and soon, colorful blooms will open. The blooms last about a week and then drop off, allowing new blooms to form. The plant will put on a gorgeous display for about a month.
Bud drop is common and can be caused by a variety of reasons: overwatering, under-watering, lack of humidity, lack of sunlight or a drafty location. To increase humidity, some growers recommend placing the plant’s pot on a saucer filled with pebbles and water. Be sure the pot is not sitting directly in water, since the water will wick into the soil and rot the plant’s roots. My Christmas cactus does not have this extra source of humidity and is growing well.
A Christmas cactus can be grown in a soil mix of equal parts regular potting soil, sand and perlite or any fast-draining soil that ensures the plant’s roots do not become too wet and rot. The plant prefers being root bound and blooms best when growing in a small pot.
From April to September, feed the plant once a month with fish emulsion fertilizer. Some gardeners also like to fertilize once a month with one teaspoon Epsom salts in a gallon of water to provide more magnesium to the plant to encourage more blooms. Stop fertilizing in late summer.
Once blooming has ended, pinch off the ends of the branches to maintain a compact shape. You can prune away up to 1/3 of the plant if it is becoming too large and unruly. The cuttings can be rooted and shared with friends. Each cutting should have at least 2-3 jointed segments in order to root well. Let cuttings dry on a paper towel for several hours before planting to avoid stem rot.
Place cuttings in the same soil mix and bury the ends about a quarter of their length. To avoid root rot, water sparingly until they have established. Don’t worry if the cuttings wilt when first planted. They will regain their vigor once roots begin to form.
If you place your Christmas cactus in the dark now for a rest and water sparingly, it will be ready to produce gorgeous blooms in December, just in time for the holidays.
Happy gardening.
• Trees and shrubs: Plant desert-adapted trees, such as Arizona ash, ascalote, chaste tree, Chinese pistache, sweet acacia, cassia, mesquite, palo verde, sissoo and Texas mountain laurel. Plant shrubs, such as desert spoon, baja fairy duster, chuparosa, hummingbird sage, Mexican buckeye, oleander, pomegranate and Texas sage.
• Native Trees for butterflies: desert hackberry, kidneywood, feather bush, desert willow.
• Annuals: Plant cool-season annuals, such as primrose, sweet peas, hollyhock, petunia, snapdragon, larkspur, pansy, calendula, sweet alyssum, bells of
Ireland, nasturtium, lobelia and stock.
Thin seedlings planted in October. Sow