December 2019 Plant of the Month

 Houseplant-wise, this is the best time of year.  Why?  Because the  “Thanksgiving cacti” (Schlumbergera truncata) and “Christmas cacti” (Schlumbergera x buckleyi) are starting to flower.

Often just lumped together as “Christmas cacti”, the two types really ARE different plants, although they want the same care, so distinguishing between the two isn’t something to obsess over, care-wise.  The true, oldey timey Christmas cactus is very, very rare in the commercial houseplant trade, having mostly been replaced by Thanksgiving cacti, which ship easier and usually bloom *before* Christmas, when shoppers are more likely to purchase holiday plants.  Thanksgiving cacti have stem segments with rubbery “horns” on them, and they have flowers with yellow/white pollen.  The true Christmas cacti have stem segments that are rounded and scalloped (no horns) and flowers that have pink pollen.  

Whichever type you have, they want the same easy care as houseplants: partial sun or very bright indirect light, and water when dry.  Ours are grown in terra-cotta pots and get watered roughly once a week.  When in doubt, wait a week.  The keys to getting either type of “holiday cactus” to flower are long, cool (above freezing) nights without artificial light after sunset October through January.  A plant right below your favorite nighttime reading lamp is unlikely to flower, but one far from artificial light after sunset will bloom.  

The biggest complaint people have is bloom drop on newly purchased plants.  The cause? Thanksgiving and Christmas cacti hate to be moved.  The first time you obtain a budded or blooming plant you may lose some flowers upon taking it home, but find it a nice spot and leave it there and bud drop will be a thing of the past.  

Holiday cacti can be grown outside in mild-winter climates, and many people do grow them outside in Chico.  It’s a bit of a gamble if we have a bad winter, but it definitely can be done.  Very bright shade or morning only sun is best.  Both types are easily propagated from stem cuttings rooted in water or directly in soil.  

If you’re not growing either type of holiday cactus, I hope you’ll consider giving them a try, and if you do, I hope you’ll let me know how they do for you.

Happy gardening!
Grant (