Thursday, January 20, 2011

What To Do With Holiday Leftovers–Part IV–Poinsettias


f59aaaPoinsettias (Euphorbia pulcherrima) are the most popular Christmas plant sold in the US.  Yearly production is about 65,000,000 plants.  That accounts for one-third of all the plants sold in the US each year!  Most are grown in California but they are also grown in almost every US state.

poinsettiasonmantelRed is still the most popular color but in the last 30 years  there have been dozens of new colors introduced.  Poinsettias come in peach, orange, gold, pale yellow, pink, mauve, burgundy and all sorts of variations, even stripes and polka dots!

Growers sometimes tint white poinsettias in colors that they can’t get genetically (like blue, green and lavender) but I expect we’ll see those colors for real, someday!

Trivia:  The Aztecs used the red poinsettia leaves to dye fabric for clothing.








Poinsettias originated in Mexico and Central America, which should tell you that they like it warm and sunny. 

Trivia:  The poinsettia is named for Dr. Joel Roberts Poinsett, an amateur botanist and first United States ambassador to Mexico who introduced it to the US.  Most botanists of his day weren’t interested in the poinsettia plant  and dismissed it as a weed but Dr. Poinsett, sent cuttings home to his greenhouse in Greenville, SC and cultivated them as gifts for his horticultural friends.


A lot of people ask me whether poinsettias are “still” poisonous and the answer is that they never were.  Lots of testing has been done on these plants, which is to say they probably fed large quantities of leaves to some poor lab animals, but chemical analysis by the National Poison Center, the AMA and POISININDEX  Service also confirms that they are not toxic. 

Trivia:  Poinsettias are very susceptible to white fly, a greenhouse pest, and insecticides sprayed on the growing plants to control it maybe be the reason why poinsettias were originally labeled as poisonous.  Those insecticides are no longer used and have been replaced with more eco-friendly controls.

The white latex sap can be a skin and eye irritant to some. I wouldn’t recommend making a salad out of poinsettia leaves (though it would look very festive), or feeding them to your domestic animals, but you don’t have to take heroic steps to keep your plants away from pets or kids.   Knowing your kids’ and pets’ habits, always use common sense in where you display any of your houseplants.


If you put your poinsettia in a warm sunny location and there are no cold drafts, it should be contentedly hanging out right now and reminding you of all your happy holiday moments. 

If it’s leafless now, it’s either because it dried out, got cold or was overwatered.   You know the pretty foil hats they wrap around poinsettia pots at the garden center?   They’re probably responsible for a lot of dead poinsettias because water remains in the bottom and can’t completely drain out.  A few weeks of well-meaning watering and you have a drowned poinsettia. 

You can try to revive it if the stems are still green by cutting them back to about 6 or 8 inches.  Make sure it’s not in a drafty area and has plenty of light, don’t let it completely dry out but don’t over water either and wait for new growth to emerge.   You’ll have to put up with people asking what you’re doing with those ugly sticks in the living room for a a few weeks so be patient.

Temperature:  Poinsettias do not like cold or drafts.  The ideal house temperature for them is around 70 to 75 degrees and 65 at night.  They can get used to colder temps with conditioning, but expect to see some leaves on the floor if you lower the heat too much or place them  near a door or drafty window.  They also like lots of light, as much as you can give them this time of year. 

Watering: They should be kept fairly moist, but never soggy.  If you’re worried about overwatering, you can let the plant dry out a bit till the top 1/2 inch of the soil feels dry to your touch.   I always check by sticking the tip of my finger down into the soil up to the first knuckle, if it’s damp, I don’t water.

Note:  If you accidentally splash water on the colored “bracts” it will stain them permanently much like water spots silk so they shouldn’t be misted or sprayed.  BTW, those fashion-colored bracts on your poinsettia are not true flower petals but modified leaves. The real flowers are the small yellow, red and green buds clustered in the center

Fertilizing:  Poinsettias should be fertilized every two weeks in spring and summer but not the rest of the year.  I stretch that out to once a month and fertilize all my plants on the same day and then mark it on the calendar.  I happen to like liquid fertilizers because they’re easier to dilute and I buy organic brands which are made from seaweed and fish by-products. (I promise to go into detail about why I use & prefer organic stuff in a future post, you’ll be surprised by my answers!)

Repotting:  Late spring or early summer is also the time to cut your plant back to about half of it’s height.  Be careful not to overwater after you cut it back.   You can repot in fresh commercial potting mix now (spring) or wait till  late summer.   My preference is for late summer because newly potted plants will put all their energy into expanding their root system to fill the pot with roots before they produce top growth.  Flowering plants usually produce more blooms if they are “pot-bound” so never go more than one size up when repotting.

Outdoors:  If you live where there’s no frost, you can plant your poinsettia in the ground. Pick a sunny well-drained area and mulch well to maintain moisture.   Just be aware that a poinsettia is a shrub and can reach a height of twelve feet!    Oh, and if you happen to get an unexpected cold snap-you’ll have leaf drop so watch the weather and cover plants when temps drop below normal for your area.    You should also select your planting sight where it won’t receive light from  street lamps.


If you live in the north, I’d wait till night temps stayed above 55 before moving my poinsettia outdoors to the deck or porch for the summer.  You can put it outside earlier if daytime temps stay around 65 and if you bring it in before night time temps fall. 

Tip: Don’t put a plant that’s been growing indoors in full outdoor sun right away, gradually move it from indirect light to full sun for a few hours each day.  This is called “hardening off”.

Cultivation:  If your poinsettia looks a little leggy (like a tall skinny super model), pinching the tips of new growth  will force it to branch out and make it a little fuller.  You can also root cuttings from new growth that you snip off.  (This is going to be the subject of a future Houseplant Friday post).

Flowering:  It’s a lot of work and probably easier to buy a new plant every year but if you really  want holiday flowers, then by September 1st, you should have repotted your poinsettia and brought it back indoors.  I wish that were all, but there’s more to it than just that.  Now comes the tricky part and why most poinsettias do not re-bloom for their owners.  From  October 1st to late November, poinsettias must have complete darkness from 5:00PM to 8:00AM or roughly fourteen hours a day.  This period of shortened days is what triggers the bracts to color and the flower to develop.


A warm closet, spare room or basement would work, if you can make sure no one turns on the lights and you don’t forget that the plant is in there.  You still have to take it out into the light during the day and water it. 

There is an easier solution though if you can find a large brown paper bag that will fit over the top of the plant.  You should be able to slip it on and off easily without bruising the petals and it should be heavy enough to block out any artificial light.

Outdoors you may have a problem if there’s a nearby street light or even a nearby window that illuminates your poinsettia.

Years ago I worked in a greenhouse where we grew over 5,000 poinsettias every year.  The light switches were taped to the off position from September to November and anyone working at night carried a sock covered flashlight pointed towards the floor to navigate.  One far corner of the greenhouse faced a streetlamp.  The two benches where only the dimmest light from that streetlamp reached, failed to develop flowers. 

Once the bracts are colored and the flower buds are showing you can stop the enforced dark period  It takes at least forty days for the flowers to form After that you can enjoy your poinsettia for the second time around!

1 comment:

  1. I'm attempting to keep mine alive enough to plant them outside in the spring. Wish me luck!! This post is a wealth of information, I'm printing it out and filing it. Thanks, Gail.


Thanks for stopping by and leaving a comment. When you do, you make my day!