Guest Author - Connie Krochmal
Shortly, garden centers will have flowering plants for the holiday season, including the ever popular poinsettia as well as Thanksgiving and Christmas cacti.
These epiphytic cacti have lovely tubular blooms that last for several days. In addition, they flower for an extended period of time with the Thanksgiving type mostly having white, pink, or red shades. Those of the Christmas cactus come in various additional colors, including magentas.
The plants are most attractive when displayed in hanging baskets. This allows the gracefully arching stems to hang over the edges of the container. Both species have spineless flat segments, though Christmas cactus tends to have rounded notches on its stems.
Like poinsettia and mums, these are short-day plants. These need about twelve hours of darkness in order to set flower buds.
The cultural requirements of both types are the same. Originally found in the tropical forests of South America. Normally, these holiday cacti grow among the tree branches where they receive lots of moisture and shade. As their light requirement is low, they do best with bright indirect sun.
For that reason, use a curtain to filter strong rays except during the winter months when more sun is acceptable. In winter, I keep mine in a window where it gets morning sun.
During the spring after frost is past, my plants continue to thrive when their containers are placed outside on a shady porch.
Unlike other cacti, these need to be kept evenly moist except during their short dormancy, occurring after flowering is completed. Until the plant resumes growth, allow the top part of the potting soil to become dry between waterings.
During the growing season, these should be fertilized about every two weeks with a high potassium, low nitrogen fertilizer. Halt applications during dormancy. Resume feeding when growth begins again.
The Thanksgiving and Christmas cacti arenít quite as sensitive to low humidity as some other flowering house plants. Average levels in the home are usually adequate.
Generally, these cacti have few problems. The exceptions are when the soil is allowed to dry out frequently or soluble salts, seen as white rings around the inside of the pot, develop. Both situations can cause stem die-back.
Prevent soluble salt build-up by watering thoroughly. Be sure water runs out the drainage holes every time you water. This procedure flushes potentially harmful materials from the soil.
One other problem that may occur is bud drop. This may occur if the plant is exposed to drafts, or extreme changes in temperature. Overwatering or under-watering can have the same effect.
Usually, these flowering plants rarely need repotting, perhaps every two or three years. This is normally done in the spring when they are actively growing. They have small root systems. So, a four or five inch pot is generally adequate.
When the container becomes crowded with the roots, repot into a new pot one size larger than the old container. A rich humusy porous soilless potting mix is recommended. These are sometimes called peat-lite mixes. If you wish to mix your own, use two parts peat moss, one part sand, and one part perlite.
These plants are easily propagated by taking cuttings, containing two or three jointed segments, from the ends of the stems. Allow these to dry for about 24 hours. Then, press the broken end firmly into the potting soil. A three inch pot is a perfect size for rooting new plants. The pieces will develop roots and begin growth within about three to four weeks. Iíve known some gardeners that also rooted the cuttings in water.
With care, Christmas and Thanksgiving cacti will bloom, providing lovely blossoms for the holiday season.