Flowers are a part of the festive holiday decorations. Some are even named for the holidays. Thanksgiving and Christmas cactus bloom in shades of white, pink and red all through the holidays. They are hardy plants needing very little care, but it is important to remember that even though we call them cactus, they are not desert plants.
Thanksgiving and Christmas cactus are actually a part of the Schlumbergera family, natives of moist tropical forests. They are succulents but need to be watered from spring until fall. Let them dry out between waterings.
Neither do these cactus need direct sun. In the tropical forest they would be shaded. The ideal location indoors is a cool room with bright indirect light..
I put my plants outside for the summer. They get plenty of water and filtered light on our piazza. I don’t bring them in until mid-September or when I start to fear a frost. Cool autumnal temperatures cause them to set flower buds even if they don’t get 12 or more hours of dark at night which is the usual advice.
When I bring them in I keep them in unheated bright rooms that are not much used, and therefore dark when the sun goes down. This regime brings them into bud at exactly the right season.
My red Thanksgiving cactus, Schlumbergera truncata, also called the crab cactus because of the sharper toothed stem segments, is well budded right now. My Christmas cactus, S. bridgesii, has smooth rounded leaf segments and a deep pink flower. It has set tiny buds that will bloom after the Thanksgiving cactus.
There is also an Easter cactus that looks similar but it is Rhipsalidopsis gaertneri and blooms in the spring. It may produce flowers at the joints of stem segments as well as at the stem ends. Its cultural requirements are also pretty much the same.
Once the buds have set, the biggest threat to blooming is temperatures that go above 70 degrees, causing the buds or flowers to drop.
All these plants can be repotted in the spring after they have bloomed. A good soil mix should include 1 part potting mix, 1 part perlite and 2 parts peat moss. Some people have good success using an African violet potting mix.
Stem cuttings can be rooted anytime except when the plants are blooming. I’ve had new plants take root when I haven’t noticed that a stem segment has broken off and fallen into the pot; this plant is among the easiest to propagate .
There is something very satisfying for the indoor gardener to have a large Schlumbergera with its arching branches and brilliant flowers with so little effort.
Even though it does not bloom during the winter holidays, I’m going to mention the orchid cactus, or epiphyllum. This is a magnificent plant, much larger than the other plants I have discussed here. The heavier fleshier stem can be three feet or longer, but can be controlled by judicious pruning. Mine has bloomed sporadically at different times. I just recently had a few blossoms, but mostly it blooms out on the piazza in the summer.
The orchid cactus is also a native of the tropical jungle and has all the same requirements as the other tropical cactus..
Last week I wrote about forcing hardy bulbs, and a reader asked me how to force amaryllis. Amaryllis bulbs are sold around this time of year, already conditioned, in order to bloom in big glamorous glory during the holidays. Each bulb will produce two or three, or even four gorgeous trumpet shaped blooms.
Amaryllis are more expensive than hardy bulbs, but they can be successfully carried over to bloom again indoors.
The bulb is large, and it is good to choose a firm good sized bulb, if you have that choice. Many garden centers sell the bulbs with a pot that is all ready to go. Even though the bulb is large, it should be given a pot that is only a little larger than the bulb, allowing about a half inch all around. Amaryllis like being potbound.
Potting soil for amaryllis should include some compost and perlite.
Fill your pot about half to three quarters full of your potting mix, set in the bulb and add more mix, firming it well, but leave the upper half or third of the bulb exposed. Watering will help settle the potting mix, and you may find you need to add a little more.
Amaryllis like to be warm (70 to 75 degrees) in a sunny location with at least four hours of direct sun a day. When it is in bloom a slightly cooler location will help the flowers last longer
Depending on the variety, the bud will present itself first. Whenever the bud appears make sure to keep rotating the pot so that the flower stalk will not lean towards the light. Amaryllis flower stalks are strong and no staking is needed.
During this growth and blooming period amaryllis should be watered well, as soon as they are dry, and fertilized every two weeks.
After blooming the flower stalk should be cut off near the top of the bulb. As with all bulbs the foliage should be left to gather new strength in the sun, because they can bloom again after a period of dormancy. I’ll revisit this after Christmas.
November 15, 2008