Thanksgiving cactus for sale in Garden Center

If your “Christmas cactus” is blooming on Thanksgiving Day, it is likely not a true Christmas cactus (Schlumbergera x buckleyi) which flowers a month or more later. Thanksgiving cactus (S. truncata) is frequently sold as “Christmas cactus”. Holiday shoppers often decorate with what’s in the store after Thanksgiving and the plants are frequently mislabeled.

Christmas cacti feature smooth round edges, while Thanksgiving cacti have pointed or jagged segmented edges. Both flowering cacti come in similar floral colors and require the same care. Both holiday cacti live for many years. In fact, you may inherit grandma’s Christmas cactus.

Indoor room temperature and daylength (photoperiod) determine flowering time. Both cacti require cool temperatures (50 to 55°F) to initiate flower buds. Locate the potted cactus near a cool window. The container can be moved outdoors on cool autumn days and brought inside when temps dip below 40°F. Holiday cacti are also “short day” plants, meaning they initiate flower buds in response to 13 or more hours of non-interrupted darkness over 6 weeks.

If you can’t precondition your plant, the side facing the window likely will develop some flower buds (unless a bright street light is nearby). The side of the plant facing a light source inside the room may not bloom because its “nighttime” phase has been interrupted by an evening light source inside the room.

Repot holiday cacti annually, preferably in late winter into new potting media. Feed the plant with house plant food such as Miracle-Gro® or Schultz® fertilizers. Use 1/2 the recommended rate and feed twice monthly from March thru December. Plant(s) can be grown outdoors in the spring and summer months under a shade tree.