How to Get a Holiday Cactus to Bloom
Got a holiday cactus? Learn the trick to making it flower.
Thanksgiving Cactus In Bloom
Bright cerise pink is a common flower color for a Thanksgiving cactus.
Julie Martens Forney
Whether you’re dressing your Thanksgiving table or decking the halls, count on a holiday cactus to bring on the color. Native to rainforests, these plants lack the prickly personalities of a desert cactus, offering greenery that’s touchable and easy to maintain instead. Flowers naturally appear near Thanksgiving or Christmas, depending on the type of cactus you’re growing.
Holiday cactus plants unfurl flowers in a hue for every décor, including bright pink, red, cream, peach, lavender, purple and white. The easiest way to add these gems to your holiday finery is to buy plants already in flower, so you know you’re getting the color you want. Plants in 4-inch pots offer a true bargain, because this is one houseplant you can easily keep alive for years to come.
Each kind of holiday cactus typically flowers around the holiday it’s named after. Both types are usually in stores during November and December. To choose a Thanksgiving cactus, look for leaves with sharp points along the edges. Christmas cactus leaves have rounded edges.
Thanksgiving Cactus Flower Buds
Holiday cactus like a Thanksgiving or Christmas cactus form flower buds in response to cool air (50-65 F) or six to eight weeks of long nights (12 hours) of darkness.
How to Get a Holiday Cactus to Bloom
Both Thanksgiving cactus and Christmas cactus form flower buds as a result of day length and temperature. Provide the right conditions in either of these categories, and your holiday cactus will form flower buds.
- Cool Air: Give your holiday cactus chilly air (50 to 55 F at night) for 6 to 8 consecutive weeks. The easiest way to do this is to place plants outdoors on a porch or other sheltered spot. Bring plants in if temperatures dip below 40 F for more than one night. (If it’s just for one night, cover plants with a thick towel.) Indoors, provide the same chill by placing plants in an unheated room.
- Darkness: Holiday cactus plants need 13 (or more) hours of darkness each night. This means total darkness—even turning on a light one time during that window interrupts the cycle and flower buds will fail to form. Holiday cacti need 6 weeks of long, dark nights to form flower buds. The easiest way to provide darkness is to place plants outdoors on a protected porch, away from outdoor lights. Short autumn days (and long nights) will do the rest. Indoors, place the cactus in an unused room, cover it or slip it into a closet at night.
Remember, you only need to give plants one of these conditions to spur flower bud formation.
The process of flower bud formation takes six to eight weeks, so count backwards from when you want the plant to flower and provide the right conditions to jump-start bud formation. The general rule of thumb for starting flower bud treatments is early October for Thanksgiving cactus and mid-October for Christmas cactus.
Once Flower Buds Form
Blossoms are long-lasting in an average home environment, and a heavily budded plant can bring on blooms for two weeks or more. Flower buds may drop before blooming if plants encounter any of several conditions:
- cold or hot drafts (keep plants away from heating vents)
- too low humidity (set plants on a gravel tray with water maintained just below the top of the gravel to increase humidity)
- too much or too little water (water plants when the top inch of soil is dry)
Flowers last longest when plants are kept on the cool side (55 to 65 F). Feed plants with water soluble plant food while flower buds are forming and until the flower show is over. After that, wait to fertilize until spring, when plants enter an active growth spurt.