How to Get a Christmas or Thanksgiving Cactus to Bloom
I think I have a Thanksgiving Cactus since it bloomed around Thanksgiving several years ago. Hasn’t bloomed since. Any suggestions how to get it to bloom again?
Thanksgiving cactus (S. truncata) has longer, more pointed leaf segments than Christmas Cactus and of course it tends to bloom around Thanksgiving rather than Christmas.
Both Christmas and Thanksgiving Cactus are called “short day plants” (phototropic plants) meaning the shorter the days (fewer hours of light) and the cooler the night temperatures the more flowers they produce. One way to encourage buds is to leave either variety outside in a protected area until the temperature gets down to about 40 degrees.
Then, if you can find a cool, bright location indoors where the temperature stays below 70 during the day and about 10 degrees cooler at night, you should have a beautiful plant for the holidays. Don’t rush to re-pot, these plants like to be root-bound. Once flower buds start to develop, holiday cacti do not like to be moved.
Here are some things you might try in order to get your Thanksgiving plant to bloom.
Room may be too warm so lower the temperature to 60-65 during the day and 55-65 degrees at night. Keep the plant in total darkness for up to 12 hours a day starting about 6-8 weeks before you want it to bloom. The warmer the room the more darkness the plant needs. The rest of the time keep it in bright lightVery few houseplants should be placed in direct sun. High light refers only to bright indirect light since direct sun often burns the leaves of indoor houseplants. An area that is too hot and dry encourages Spider Mites and causes blooms to quickly fade. A northern exposure really doesn't provide enough light for high light plants. These plants need to be placed directly in front of an east-facing window, within 1-3 feet of a west-facing window, and within 5 ft. of a south facing window. A high light area has over 300 ft. candles of light.. Starting in the fall, feed your plant with a fertilizerPlants need fertilizer only when they are actively growing. Slow growing plants in low light require very little plant food. Too much fertilizer is worse than not enough. Most plants prefer a water soluble plant food at 1/2 the recommended strength. Plants that are in bloom or dormant should not be fertilized. Houseplant food contains nitrogen (N), phosphorus (P), and potassium (K). A fertilizer containing these elements in equal proportion is considered a balanced plant food. Nitrogen helps in photosynthesis and encourages the growth of leaves and stems. Potassium and phosphorus also help in photosynthesis and aid in root and flower development. Most fertilizers have trace elements of other minerals that are lacking in the soil but are necessary for good plant growth. Fertilizers have a high salt content. If a plant is not producing new leaves and doesn’t absorb the fertilizer, salts build up in the soil. These salts can burn the roots, discolor the leaves, and cause new growth to be small. high in potassium and phosphorous but low in nitrogen. Always dilute it to 1/2 the recommended strength.
Cool temperatures and hours of darkness are the key!