Friday, January 11, 2013
How to Care for Christmas Flowers Year-round Part 3
Christmas Cactus: There are several plant species that are called Christmas cacti, but the true Christmas cactus is the plant, Schlumbergera x buckleyi, a hybrid of some very similar holiday cacti, and is a very common plant in cultivation. These are relatively easy plants to take care of, safe (no spines or toxins) and can live a long time (generations). I have a cutting of one that originally belonged to my husbands grandfather that was very old and very large. I also have the closely related plants Thanksgiving Cactus (due to the timing of the plant’s affinity to bloom around Thanksgiving), and Easter cacti. These plants are nearly identical to Christmas cacti but tend to either have sharper node tips, or much blunter node tips and bloom at different times of the year.
Schlumbergeras are epiphytes in nature (grow on other plants or non-soil surfaces), from the high elevation jungles of Brazil. Their natural environment is a relatively cool even temperature, high humidity, bright light with little direct sunlight, and frequent rain.Considering this it is a little amazing how well they thrive as potted plants in normal cactus soil and in a warm temperate climate, or indoors.Though these are indeed true cacti, they do not look like the cacti most are normally used to seeing. These plants are fleshy, green, segmented plants that, over time, develop woody, thick stems. Thankfully they are basically spineless.
It's no surprise that, Christmas cacti require different care than do most cacti. Even though they come from tropics, they live in a relatively cool environment and therefore do NOT like high heat like desert cacti do. Basically all cacti are summer growers and spend winter very inactive in terms of growing or flowering. This is true of Christmas cacti as well. Despite their blooming in winter, they do very little growing in winter, but it is still the best time of year to enjoy Christmas cacti. They don’t like temps much over 80 degrees anyway. On the other hand they cannot tolerate freezes either, and prefer temps above 55 degrees. Outdoor plants seem to cope with temps into the low 30's but are not happy about them. Leaves change color due to cold. So if you keep them outdoors and cold weather is coming, bring them in.
And unlike most cacti, Schlumbergeras do not like full sun, particularly when it’s hot. But they do like bright light and grow and flower best if the light is very bright. They will tolerate low light situations for short periods of time, and that is why they do so well as indoor plants. A few days in the middle of the table far from windows will not do them much harm. But they do need to be returned to an area of bright light soon after, or blooming might cease early. My cacti do best when kept outdoors under a shady tree or porch when it’s warm and I move them back indoors near a bright window as it gets colder around 55 degrees. In warmer climates these can be kept outdoors year round, but still don’t try to grow them in the garden like one would a regular cactus. Freezes will damage them, but it takes a pretty severe freeze to kill one in a warm climate.
Schlumbergeras need to be planted in well draining soil. Remember in the wild they basically live in soil-less situations, so water needs to drain past the roots easily, or they could rot. Under-watering will kill a Christmas Cactus, too, but a lot more slowly. There is time to intervene should the cladodes appear flattened and wrinkled. Schlumbergeras are from high rainfall and high humidity environments and do appreciate being watered regularly. My plants seem to do well in soil formulated for cactus.
Once the days shorten (usually in October), back off on watering. Some recommend NO water the entire month of October, and then resume again in November. Then it is recommended to withhold water again once blooming is over for a bit longer than a month this time. If signs of new growth appear, it’s time to start watering again. This is also a good time to re-pot the plant and put it in some new, clean, well draining soil. Re-potting is recommended every few years.
Fertilization should be with half strength water soluble formulas and only in warmer weather. Wait until new growth is seen and time for re-potting. If using a granular fertilizer, it is best to be stingy- these plants do tolerate fertilizers better than do most cacti, but still, be careful. 10-10-10 is the best ratio to use.
For plants that are not flowering as expected:
Be sure the soil is not too dry, or plants are not next to a cold or hot source (air conditioner, heater etc.). If there is some night light on the plant, it might retard it from blooming. Put these plants in a totally dark room for a minimum of 13 hours a night. This will also help these plants bloom when wanted, and not too early. These plants may need longer light to simulate early fall, rather than late fall, to keep them from blooming too early. Then do the total darkness thing about 4-6 weeks before the time blooming is desired, every night until buds form and the plants can be returned to their location near the window or table. And be sure the daytime temps are in the 60's (hot houses will prevent these from blooming) and night temps are not much below 50 degrees. Sometimes a little liquid fertilizer with extra potassium can help stimulate blooming. Once flowering starts, it is recommended not to move these plants too much, in terms of overall heat and light, or they may abruptly stop blooming and drop all their buds.