Ask the Agent/Master Gardener: Holiday Plant Myth Buster Edition

Every year, when the holidays roll around, extension agents and master gardeners often find themselves facing questions about holiday plants.  Let’s face it – many holiday traditions involve plants and plant life, so there are going to be questions.  Given the number of old wive’s tales and urban legends surrounding holiday plants and their care, it’s a good thing that people ask questions.  I’ll try to briefly (well, as briefly as I can) answer some common questions and dispel some common, pesky rumors.  Here we go:

Question 1:  How do I keep my (child/dog/cat/other creature I care deeply) about from eating the poisonous poinsettia? 

Answer: Take a moment and breathe deeply.  There’s not as much to fear here as you think.  Poinsettias have been much maligned throughout their history and their “toxicity” has been largely overblown.  These plants do have a latex sap that may cause skin irritation if touched or stomach problems if ingested, but don’t expect little Timmy or Fido to fall over if they accidentally eat a leaf.  In fact, the over 20,000 reported cases studied by the American Journal of Emergency Medicine showed no serious effects or fatalities among poinsettia taste testers. 


The rounded stems and flowers of the Christmas cactus

Question 2: How do I get my Christmas cactus to bloom?  How do I keep it alive?

Answer: Are you sure you have a “Christmas Cactus”?  I’m willing to bet a small sum that a majority of people, in fact, have a ThanksgivingCactus.  There are two major species of Schlumbergera cactus that bloom around the holidays.  Cultivars and crosses of Schlumbergera truncata are Thanksgiving cacti and can be identified by their spiky stems and zygomorphic (flat on the bottom – bilateral symmetry) flowers.  The flower shape often leads to its nickname – the “Zygo cactus”.  Schlumbergera russelliana was the major parent of a group of cacti known as the Buckleyi group, which are the true “Christmas Cacti”.  They can be identified by their rounded stems and rounded (radial symmetry) flowers. Thanksgiving cacti are more commercially available because they are in bloom for the start of the shopping season and they have  more upright (easier shipping) habit.

The zygomorphic flowers and spiky stems of the Thanksgiving cactus

Now, to take care of them you have to realize that these are not desert cacti.  These are rainforest cacti.  Their native habitat is living in trees in Brazil, so you want to keep them in a very light, peaty soil mix.  You’ll also want to let them dry slightly between waterings, but don’t think that they like to live the life of dehydration – you do need to keep them watered.  Their flowering is day length dependent.  They are short-day plants (more accurately, they are long-night plants).  For their flowers to begin forming, they need several treatments of long, uninterrupted night periods of at least 12 hours.  This occurs naturally about mid-October, but you can delay flowering by using grow lights to lengthen the day.  If you cactus does not flower, you need to move it to a spot where it gets at least 12 hours of relative darkness to initiate blooms (keep away from indoor light sources or windows near outdoor lights).


Question 3: Should I add bleach, aspirin, sugar, or other preservatives to my Christmas tree water? 

Answer: The short answer is NO!  Many folks fall for the old urban legends of using additives to reduce fungus, preserve trees, etc.  The National Christmas Tree Association (it’s a marketing group, not a social club for conifers) recommends using only fresh, clean tap water for your tree.  Even the real “Myth Buster” guys agree.  Municipal water is fine, as the low chlorine level will not harm the tree and will retard fungal/bacterial growth for a very short period (it evaporates pretty quickly). 

Do you have any holiday plant questions?  Have you heard of any crazy holiday plant myths that need busted?  Add your comments to keep the conversation going.