You’ve seen them. The saddest thing ever – a poinsettia, still in its little foil sleeve, tucked into the corner of the doctor’s office/bank/etc. In June.
Photo courtesy of Beth Bonini http://beedrunken.blogspot.com
So iconic, there’s even a rock band in St. Paul called “Dead Poinsettia.”
Every year about this time, I get asked “how do I care for my poinsettia so it will bloom next year?” by friends, students, random callers, and random newspaper writers.
Two words: Chuck it.
1) Unless you have a greenhouse, you probably can’t replicate the growing conditions that resulted in that lovely, leafy, perfect plant. That poinsettia has been grown under optimal temperature, humidity, fertilizer, and high light conditions. It’s also been sprayed with plant growth regulators – often multiple times, to keep the internodes from elongating. Even with all the breeding for a compact habit, they still want to streeeeetch to be the shrubs/small trees their forefathers were back in Mexico.
2) Day length. Poinsettias are obligate short-day plants, which means they require a long dark period (yes, I know, why don’t they call them obligate long night plants) to become reproductive, resulting in red (or pink or cream) bracts and the little yellow flower-thingy in the center (the cyathia). You can, of course, stick it in a dark room at 5:00 p.m. and remove it to a lighted area at 8:00 a.m., every day for the months of October and November. Until you forget over that long weekend and leave it in the dark for three days…
3) Help stimulate the local “grower” economy. Consumerist, I know, but wholesale and retail greenhouses grow poinsettias to keep their full–time employees working during what is otherwise a very dead time in the ol’ floriculture business. Seldom do these businesses make much of a profit on poinsettia; the plan is to keep everyone busy and generate a little cash flow. Now, some growers/garden centers go above and beyond the usual 6” red point, with unusual cultivars in a range of colors and sizes, hanging baskets, poinsettia “trees”, etc. This has proven to be a great strategy for some enterprising growers.
4) Poinsettia = total whitefly magnet.
In light of the above, I recommend enjoying your poinsettia until the leaves start dropping…then once it reaches the “less than fresh” stage, add it to the compost pile. Next season, go to your local independent greenhouse or garden center and buy a new one. Finally, if you are one of the hard-core, stick-with-it types that has been successfully reblooming the same poinsettia for three years running, congratulations! You have much, much more patience than I do.
Disclaimer: My Master’s research was on poinsettia and the effects of nitrate- N:ammonium- N ratio on growth thereof. Five treatments x 6 replications x 3 cultivars = 90 poinsettias, off of which I picked every leaf and bract to run through a leaf area meter. The latex oozing from the petioles made for a gloppy mess and the whole process took five days. Even 15 years later, I can barely look at a poinsettia without cringing. Pleh.