A frozen poinsettia is a big disappointment if you’ve just bought the plant to decorate for the holidays. These Mexican native plants need warmth and will quickly get damaged or even die in colder temperatures. Depending on how long you left the plant outdoors or in a car, and the temperatures, you may be able to save and revive your poinsettia.
Avoiding Poinsettia Cold Damage
It’s better, of course, to prevent damage from the cold than to try and correct it. This popular seasonal plant is common in cold climates around Christmas, but it is actually a warm-weather species. Native to Mexico and Central America, poinsettias should not be exposed to temperatures below 50 degrees F. (10 C.).
Even leaving a poinsettia outside when it’s around 50 degrees regularly or for extended periods of time can cause damage. When purchasing a potted plant, make it your last stop on the way home. A poinsettia left in car temperatures in winter can be damaged irreparably.
Also, although it may be tempting to put a poinsettia outdoors for holiday decorations, if you don’t have the right climate, it won’t survive. The hardiness zones for the plant on the USDA scale are 9 through 11.
Help, I Left My Poinsettia Outside
Accidents happen, and maybe you left your plant outside or in the car for too long and now it’s damaged. So, what can you do? If the damage isn’t too bad, you may be able to revive the poinsettia and even keep it happy enough to give you another holiday season of colorful cheer.
A poinsettia damaged by cold will have dead and dropped leaves. If there are any leaves left, you may be able to save them. Bring the plant inside and trim off the damaged leaves. Put it in a spot in the house where it will get at least six hours of light per day. Indirect light is best, such as a west- or east-facing window or a bright, open room.
Keep it away from drafts and ensure the temperature is between 65 and 75 degrees F. (18-24 C.). Avoid the temptation to put your plant too close to a radiator or heater. Extra heat will not help.
Water the poinsettia every few days to keep the soil moist but not soaking. Ensure the pot has drainage holes. Use a balanced, houseplant fertilizer as directed on the container once the midwinter growing season has passed.
Once you have warmer weather, you can take the poinsettia outside. In order to get it to bloom again for the holidays, however, you must give it 14 to 16 hours of complete darkness starting around the end of September. Move it into a closet each night. Too much light each day will delay flowering.
There is always a possibility that it is too late to save a frozen poinsettia, but it’s worth a try to revive it if you see some undamaged leaves.