(First published in the InterTown Record in three parts in 2018)
As it is so often, research into a particular plant has my head spinning. What I’d always assumed, is not necessarily true, and various websites have slight differences in their explanations.
Schlumbergera bridgessii is the scientific name for Christmas cactus. The cultivars are also known as Thanksgiving cactus, crab cactus and holiday cactus. Christmas cactus is not really cactus but a succulent. Wikipedia says, “Nearly all cacti are succulents, but not all succulents are cacti.” (Succulents are plants with parts that are thick and fleshy which enable water retention in arid conditions.)
One site said the Christmas cactus does not naturally exist in nature. It was bred from two other plants grown in the rainforests of Brazil. It has segmented, flat stems of a glossy green which can hang down about 36 inches. Flowers form on the ends. The bright blossoms are unique in that they may have several tiers of petals making the entire flower up to 3 inches long. Each one can last for several days, and the entire blooming period spans several weeks.
Because the plant comes from rainforests it prefers humidity and requires more water than what one would assume of a cactus. Homes around here can be very dry. A little extra care in the winter may require putting the cactus in a pebble tray. Place pebbles in the tray and add a little water. Don’t cover the pebbles. Set the cactus pot in the tray but not so the plant itself is sitting in the water. The evaporating moisture will help provide humidity. (I bought a couple of cheap, pretty trays at Family Dollar and with colorful stones and/or river rocks added, it makes a cute setting).
Basic care of a Christmas cactus is keeping it out of drafts, watering when it feels dry, providing adequate light and occasional feeding. One thing of interest, though, is that Christmas cactus requires a certain amount of darkness.
I think my Christmas cactus liked me writing about it last week. (Doesn’t most everything like a little attention?) The plant has sprouted more and looks vibrant. Oh OK, perhaps it’s because I’m giving it more water now that I understand it’s not a real cactus.
Speaking about watering, here are some tips. Water when the top inch of soil feels dry. Soak the soil until water runs through the pot’s drainage holes. Give it a few minutes then discard any excess water in the drip pan. If you use a pebble tray let the extra water in the tray evaporate to provide humidity around the plant. Just make sure the plant isn’t sitting directly in the water (which could cause brown spots, or root or stem rot). Pebble trays and the pebbles need periodic cleaning.
A mild household plant fertilizer is beneficial, too, about every other week. However stop feeding a month before the plant will bloom, usually late summer and fall.
I learned two “thermo-” terms in this research regarding blooming and achieving the best growth in plants. Thermo-periodic is the technical term used for the amount of day light time the plant is exposed to in a 24-hour period. Thermoperiodism refers to the day and night temperature fluctuation surrounding the plant.
Christmas cactus likes indirect sunlight and does best in east or north-facing windows. It can adapt to low light conditions but will bloom better in bright, indirect light. Too much direct sunlight may burn the leaves. Ideal day temperatures should be around 70 degrees and evening temperatures 60-65 degrees.
I mentioned last week about the ability to choose when you want your cactus to bloom. Of course most people want theirs to bloom around the fall/winter holidays, although the plant can also bloom during the summer. If you want more control, whatever date or holiday you choose, simply cut back watering and hours of daylight six to eight weeks before you want it to bloom.
This will force the plant to go into its dormancy/rest period. (Whether you are trying to change its regular bloom time or not, it still needs a period of dormancy.) It will also need more darkness; 12-14 hours of total darkness, meaning no indoor light or neighbors’ lights. (I have neighbors who leave their outside lights on all night.) Some people cover the plants or put them in a closet. Dormancy temperature is best at 50-60 degrees. It the temperature is over that, the plant will need 15 hours of darkness.
New buds will eventually begin to appear and, at that time, increase the water times – but not the amount. Buds will fall off with too much water or if the pot is moved around. Blooming time is usually four to six weeks in bright, indirect light. The flowers can last up to nine days.
Once flowering time is over, the plant can be trimmed back for uniformity. Pinch off enough sections to achieve the shape you want. Normal watering and fertilization can begin when new growth appears.
To continue about Christmas cactus care: Christmas cactus prefers snug pots with its roots tightly confined in well-draining soil. This snugness helps the root system produce better blooms. The plant will only need to be repotted every two to three years.
Repotting is usually best done in spring or early summer when the plant is not blossoming. This allows the plant time to acclimate before blooming again.
Pruning helps keep the plant healthy, keeps it shaped and confines the growth to the available space in the home. Pruning also encourages the plant to branch out and start growing again. Give it about a month to rest after the blooming period is complete, though. To prune, gently twist the stem between the segments on the stem and remove the section. Up to 1/3 of the Christmas cactus can be removed each year without causing damage to the plant. Sections trimmed off can be placed in a new pot to create more plants. Bury the last segment in potting soil.
Fertilize with a houseplant fertilizer April through October. The plant can be moved outside to a shady spot in the summer until temperatures drop below 50 degrees.
Two issues with these plants are stem rot and root rot.
Root rot can happen if the roots sit in wet soil. The plant can be saved if the damaged root can be removed. However if the rot has moved up the stem, stem rot, a fungal problem, occurs. If this happens start a new plant before the infection spreads too far.
My Christmas cactus had two more blossoms during the third week of February.