How to Get a Christmas or Thanksgiving Cactus to Bloom

Hi Bobbie,

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 light. Starting in the fall, feed your plant with a fertilizer 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!