By: Mary Townsley, PhD, Mobile County Master Gardener, www.MobileCountyMasterGardeners.org
This time of year, grocery stores and holiday markets like to tempt us with colorful, flowering "Christmas cacti.” There are many cultivars, so you might find holiday cacti with red, pink, white or even yellow blooms. Did you know that these holiday cacti are related to prickly pears and giant saguaro cacti? Holiday cacti are indeed in the cactus family, but as native plants they live in the coastal mountains of Brazil rather than arid deserts.
Holiday cacti are named for the time of year they typically bloom: Thanksgiving, Christmas or Easter. But there is a catch...just because it is Christmastime, and your cactus is blooming merrily, does not necessarily mean you have a Christmas cactus. So is my gorgeous new plant really a Christmas cactus? If not, then what type of cactus is it? How can I tell?
Part of the confusion arises from the fact that these cacti are short-day photosensitive plants. That means they only set flower buds and bloom when the plant has experienced the appropriate term of short day (long night) lighting - at least 12 hours in the dark each day - and cool nighttime temperatures - 55-65 degrees. Thanksgiving and Christmas cacti require 5-6 weeks of short days, while Easter cacti require a much longer period of short days for flower buds to set. Growers will often artificially control the environment for holiday cacti to induce blooming in time for the end of year holiday market.
So, if blooming time is not a reliable way to identify my holiday cactus, what other features can I use for identification? There are three physical characteristics to look for that will help you correctly identify your plant: the "leaf" shape, the color of the central anthers in the flower - the part of the flower that produces pollen, and the flower shape itself. Note that holiday cacti really don't have leaves; rather, the arching, segmented, sometimes-branching forms that develop flower buds at their tips are actually flattened stems. Each type of holiday cactus has unique, identifying characteristics.
Thanksgiving cactus - Schlumbergera truncata: The stems on these holiday cacti have teeth: 2-4 saw-toothed projections along each side of the stem. Somewhat appropriately, these cacti are sometimes called crab cacti! The anthers in the flower are yellow. The tubular flower itself angles from the end of the stem to hang horizontally.
Christmas cactus - Schlumbergera bridgesii or Schlumbergera x buckleyi: There are no teeth!! The stem margins of Christmas cacti are smoother than those of Thanksgiving cacti. The anthers in the tubular flowers are pinkish/purplish brown. The flower itself hangs in a straight line from the stem.
Easter cactus or Rhipsalidopsis gaertneri: The segmented stems have rounded or scalloped margins, again without teeth. The flowers have bright golden anthers and are star-shaped rather than tubular. These cacti are less commonly found in markets as they apparently are more finicky to grow.
Well, you might not really care what kind of holiday cactus you have, but just want to enjoy this plant for years to come. Great! Here are some care tips.
· As a cactus, good drainage is a must. Let the soil dry out completely between waterings. If you repot your plant, use a planting mix with at least 40% perlite to allow for that drainage.
· If indoors, provide your cactus with indirect light - keep it out of direct sunlight. To ensure reblooming, in the fall put the plant in an area that gets little or no nighttime artificial light with cooler nighttime temperatures.
· If you move your holiday cactus outdoors for part of the year, be mindful that they are not tolerant of long periods of direct sunlight or of cold and frost. A south facing shaded porch can be a great location. Bring the plant indoors when nighttime temperatures dip below 55 degrees.
Easter Cactus
Comments