Invest in New Poinsettias Every Year, or Prepare to Invest Plenty of Time
Q: Is there any way to save a poinsettia from one Christmas to the next and have it look as good the following year? I’ve had some luck with keeping the plant alive, but it never looks as good the following year.
A: First of all, let’s set some reasonable expectations. Even if you do nurture a poinsettia from one Christmas season to the next, it will never look quite as good as it did when it first arrived at your home. Those lush, full leaves and colorful bracts are the result of months of tending in carefully controlled conditions that most of us lack the facilities, time and inclination to replicate. But you can keep your poinsettia alive and have it look respectable the next year.
Poinsettias are one of the heralds of the holidays. They come with bracts in shades of red, pink, mauve, white, burgundy and yellow, with tiny flower clusters in the center of each group of colorful bracts. They are not poisonous, despite well-traveled myths to the contrary, but many people are sensitive to the sticky, milky sap, which contains latex and is common to members of the spurge or Euphorbiaceae family. Euphorbia pulcherrima gets its common name from Joel Poinsett, the U.S. ambassador to Mexico who admired it so much he introduced it in this country around 1825.
The first thing you need to do when you get that gorgeous poinsettia home is remove the foil paper wrapping. It dresses up the plain plastic pot but it also prevents air from circulating around the stems near the soil, which can lead to fungus and rot. Find a slightly larger decorative pot to set the plastic pot in if you’re concerned about appearance.
Set the plant in a location free of drafts and extremes of heat and cold; you don’t want it near a heating vent, the door or the fireplace. Bright, indirect light is best, because a sunny window could burn it up. Water it when the soil surface is dry but make sure you empty the drainage saucer immediately after the water has run through the pot. Poinsettias come from the tropical desert, not the tropical jungle, and they don’t like wet feet. Water left in the saucer can wick back up into the pot. More people kill poinsettias — indeed, most houseplants — by overwatering than by under-watering.
Most houses lack humidity in the winter, so providing a little extra moisture in the air around your poinsettia will prolong the color in the bracts. You can either mist the plant every day or two, or set the pot on a tray filled with about an inch of gravel. Add water to the tray so that it comes to just below the top of the gravel. It will evaporate up and around the plant. Be sure to check the water level in the tray daily. Don’t fertilize it yet.
After the holidays, you have two options. You can keep it in a pot, or plant it in the ground. Either way, you’ll need to keep it in the house until all danger of frost has passed. Keep the plant fairly dry — a light watering once every week or two should be sufficient — and move it to a cool, out-of-the way location, because it’s going to look a bit bedraggled. Once the weather warms, cut it back to about 4 to 6 inches on each branch. If you’re planning to keep it as a potted plant, move it outside to a somewhat shady spot and fertilize with a balanced fertilizer. Gradually increase the amount of sunlight your poinsettia receives, remembering that everything in our area appreciates shade in the late afternoon. If you move it out when the weather first warms, as it tends to do in February, be aware that you might have to move it back inside if a freeze is forecast.
If you want to plant it in the ground, wait until after all danger of frost has passed. Select a site with full sun and fertile, slightly acidic soil, which ideally is about 6.0 pH, but anything between 5.0 and 7.0 should be fine. Considering the amount of work you’re going to have to do to get this plant to behave as you want it to, you might want to get the soil tested first. Kits and instructions are available at no charge at the Leon County Extension Service; the lab in Gainesville charges a nominal fee to analyze your soil sample.
Set it at the same level it was in the pot and water thoroughly to remove air pockets. Feed it with an all-purpose (15-0-15) fertilizer monthly from May through September. Keep the soil evenly moist but not wet. Pinch back new growth throughout the summer to promote a bushy shape, but stop pinching around Labor Day, to give the last flush of growth time to initiate flower buds.
Now here’s where the work comes in, whether your plant is in a pot or in the ground. It is essential that your plant be in complete darkness — no streetlights, no security lights, no glow from the window — for 14 hours a night for six to eight weeks before flowering. If your plant is in the ground, cover it in the evening with a cardboard box and then throw an old quilt or bedspread over it, making sure it is completely covered. Take it off the next morning, 14 hours later. Do this every single day for six to eight weeks. Every day you miss is a day’s delay in blooming. If your plant is in a pot, do the same thing, either on the porch or in the house.
You’ll have to protect a poinsettia in the ground from freezing, just as you would any tender perennial. This is definitely a high-maintenance plant. Given the great variety of colors and the reasonable prices, I usually don’t bother trying to save mine from year to year. However, most gardeners have a plant or two they treasure and are willing to devote a lot of effort to maintaining, and if a poinsettia is yours, give it a try. You can always buy another one if you don’t like how it looks next year.
©2013 PostScript Publishing, all rights reserved. Audrey Post is a certified Advanced Master Gardener volunteer with the University of Florida/IFAS Extension in Leon County. Email her at Questions@MsGrowItAll.com or visit her website at msgrowitall.com. Ms. Grow-It-All® is a registered trademark of PostScript Publishing.