CHRISTMAS CACTUS (SCHLUMBERGERA)
Two simple but slightly different species of Schlumberger are commonly grown houseplants which have been the basis of many questions asked at Government House. Schlumbergers Bridgesii, the Christmas Cactus, has smooth stem segments while S. Truncata, or Crab Cactus, has hook-like appendages on each stem segment. They have been hybridized so that varying stem shapes appear as well as eye-catching 3 inch cerise, salmon, pink, violet, and multi-coloured flowers in November/December months. They are Epiphytic Cactuses native to the jungles of South America.
If purchasing a plant in bloom, place it in a bright spot out of sunlight as too much light will cause the leaves to turn yellow. Average household temperatures seem to be more than sufficient for these beauties. From the time they begin their festive season to early spring, our normal practice is to keep the soil constantly moist and feed with 20-20-20 every other week. Most publications advise on setting the plants outside for the summer in a shady spot and bring them inside before the first frost. While this recommendation is more than acceptable, at Government House we have the luxury of a heated greenhouse which permits us to rest plants underneath the existing benches, simulating outside conditions.
It is not particularly difficult to get the plants to blossom as long as they’re given some special attention after their rest period from early September until flower buds form. Flowering is related to the length of the day and to night temperature. If the fall nights are in the 50 to 55° range, 10 to 13°C, the buds will form regardless of how many hours of darkness they receive. But if the night temperatures are in the 60 to 65° degree range, 16 to 18°C, as a precaution it is best to ensure plants receive 13 hours of uninterrupted darkness every night. Either place the plants in an unused room or cover them with a dark cloth if they’re in a lighted room. If the outdoor technique is utilized up until late September, it is likely they would have received enough cool nights to form buds by the time they are brought inside. During the fall, while the buds are forming, fertilizer should be stopped and plants given only enough water to keep the green stems from shriveling.
Once the flower buds appear, the night temperatures and hours of darkness no longer matter and the plant can be placed in the desired location. From the time the buds appear, the soil must be kept moist and feeding provided every other week.
I find our Christmas Cactus flowers best when they’re rather pot-bound, but if they become too crowded for space, they don’t seem to bloom well. So when we notice a loss of flower production or if its been several years since it was last repotted, we move them to a larger pot in the spring. We also use a one inch increment in pot size to ensure plants remain somethwat pot-bound providing an abundance of bloom.
They are extremely easy to propagate. At anytime during the year, simply take a stem tip cutting and insert it into sand or peat moss. Keep slightly moist and enjoy.
Since this is my last entry for this year, I would like to take the opportunity to wish everyone Happy Holidays and a productive New Year.