Who among us didn't have a grandmother whose dining room table wasn't centered by at least one holiday cactus plant?
OK, maybe the plant wasn't the at the center of the table, but I would be willing to presume there was at least one Thanksgiving, Christmas or Easter cactus somewhere in the house.
Our grandmothers probably didn't know that the plant they lovingly coaxed into bloom on each of those holidays was not from the dry, arid desert we most often expect a cactus to grow. The term "cactus" is pretty much relative anyway. The naming of cacti has been a constant headache for enthusiasts of the plants, mainly because no one has been able to come up with a standard that differentiates from the many hundreds of cacti species.
But rather than make this too complicated, I will simply tell you that Thanksgiving and Christmas cacti belong to a genus of plants called Schlumbergera, named for Frederic Schlumberger, a 19th-century French cactus collector. It might also be helpful to know that Thanksgiving cacti were formerly called Zygocactus. The reason you might like to know this is because sometimes they are still labeled this way by commercial growers.
The common name of these cacti is also misleading. Some plants labeled as Christmas cactus (Schlumbergera x Buckleyi) will bloom as early as November. Thanksgiving cactus (Schlumbergera truncata) is often mislabeled as Christmas cactus. And while the Thanksgiving cactus traditionally blooms four to five weeks earlier than the Christmas cactus, some growers have crossed the two plants into something that blooms at varying times between the two. I can't tell you the number of people who have said to me, ''I have a Christmas cactus, or it could be a Thanksgiving cactus. I don't know what it is.''
If you really want to know what type of cactus you have, you have to look at the shape of the leaves.
The leaves of holiday cactus resemble segmented thick pad-like structures, joined from one to another. The flowers emerge from the tips of the leaf chains. Leaves of the Thanksgiving cactus are serrated with ''toothed'' leaf segments. Christmas cactus leaf segments are rounded. The Easter cactus (Rhipsalidopsis gaertneri) is a plant from an entirely different genus and blooms in early spring. Its leaves are thickly ridged to form a three-dimensional triangular shape.
The plants we often buy are likely from six species of epiphytes, which are tree-dwelling plants from the rain forests in Brazil. The leaves are flat and shallow so that water can easily run off, creating dryer conditions. In our homes, these plants should be grown in containers of rich, organic soil. The soil should be kept moist while the plant is in bloom, but can be left to dry out between waterings when the plant is not blooming. Be sure the container has drainage holes so the plant isn't sitting in muddy soil. In the wild, the plant enjoys filtered bright light from between the leaves of its host tree. At home, the plant should be kept in a sunny window with some protection from the heat of the sun through the glass, usually in the form of half-opened blinds or sheer curtains. In summer when most people move their indoor plants outside, place your cactus under a patio roof or tree where it can receive indirect light in early morning, but shade when the sun is at its brightest and hottest.
If you admired one of these plants in someone's home, it is likely you came home with a few segments of leaves. These plants are extremely easy to grow from cuttings. Simply put a leaf segment into moist soil and in a few weeks, roots will form and new leaves will grow. Depending on the variety, plants can grow upright or with long, pendulous leaf chains. Blooms can be red, pink, orange, white or purple.
If you can't to get your plant to bloom, it could be because it needs long periods of total darkness and cool night temperatures to form buds. Beginning mid-September, place the cactus in a closet or cover it with a large, brown paper bag from about 6 p.m. to 8 a.m. However, if you keep your cactus in a cool room, around 50 degrees in September and October, the plant is likely to bloom even without the dark period. Fertilize when buds begin to form with a houseplant fertilizer according to the manufacturer's directions.
Evanoff is a Master Gardener with The Ohio State University Extension of Trumbull County. She can be reached at firstname.lastname@example.org.