Despite being a tropical plant that is native to Mexico and Guatamala, perhaps no plant is more widely associated with the winter holidays than the poinsettia (Euphorbia pulcherrima). With its flower-like leaves in vibrant shades of red, pink or white, it's a traditional holiday gift and popular home decoration. During December they're commonly seen on kitchen islands and coffee tables. Some people keep poinsettias alive year round indoors, though they do not bloom all year. Where you don't often see a poinsettia is outdoors, which leads to the question, can this poinsettias live outside in winter?
How Cold Can Poinsettias Get?
The poinsettia is not very cold tolerant, and freezing temperatures will kill your plant. Temperatures below 50 degrees Fahrenheit might cause the plant to weaken somewhat, and the ideal temperature range for your poinsettia is between 65 and 75 degrees. However, it may be possible to put your poinsettia outdoors for short periods of time in winter (say for a few hours as a decoration for a holiday gathering), if it doesn't get too cold outside.
Check Your Hardiness Zone
To determine if it's too cold in your region for a poinsettia to live outdoors, you need to know your hardiness zone. The easiest was to do this is simply to do an internet search with your zip code and the words "hardiness zone" and it will give you the specific USDA zone. Most places in the US are between 3 and 10, and some have narrower ranges like 5 to 8, or 8 to 11. The poinsettia's growing zone is between 9 and 11, so it is incapable of surviving planted outdoors in colder zones. However, there may be ways to display your poinsettia outside safely for short periods of time in winter.
How to Keep a Poinsettia Thriving
There are a few tips for keeping your poinsettia happy and healthy, ensuring it will bloom and stay vibrant looking. The main thing to keep in mind is that the poinsettia is a somewhat sensitive plant that needs specific conditions to thrive. For example, it needs a prolonged period of time in darkness (14 to 16 hours per day) to form the colorful leaves that make it so loved. The most common time for this is October and November, when it goes dormant for a time and forms new leaves, so it will be ready for "blooming" during the winter holidays. A poinsettia is not only quite sensitive to temperature, but is sensitive to cold drafts, so it's best to situate it away from a door or drafty window.
Keeping Your Poinsettia Outside
Given the poinsettia is a tropical plant that prefers warm temperatures and is not suitable for the cold, is it ever possible to keep it outside in winter? The answer depends entirely on how cold it gets where you are. If the temperature's not going to drop below 60 degrees, it should be fine. Keep it watered and out of high winds. Below 50 degrees, the poinsettia may be in danger of dying if left exposed, so keep an eye on the thermometer.
- But what if you want to keep your poinsettia outside in colder temps for holiday decor? Though it may not seem like a good idea, there are some tricks for keeping your poinsettia alive outside.
- Don't keep it outside for long periods of time in the cold.
- Don't ever put the poinsettia outside if temperatures are expected to drop below freezing (32 degrees). If the soil freezes, or the leaves freeze, your poinsettia may die. Don't leave the poinsettia outside all night in the cold; bring it back in to protect it from temperatures dropping in the middle of the night.
- If you place the poinsettia in a sunny spot during the day, it may be okay for a few hours, but keep an eye on the temperature. Soil conditions will also affect its cold hardiness.
Soil and Container Suggestions for Keeping a Poinsettia Alive in the Cold
Some container materials make for colder soil conditions because of they way they conduct cold and heat. Metal will tend to get very cold, ceramic less so, whereas wood, resin or plastic containers take longest to react to cold and will not retain cold as much as metal or ceramic. Having good quality potting mix that is fairly fresh will also help; older potting mix will tend to grow thin and porous and this might make it more susceptible to freezing.
Watering Your Poinsettia
Your poinsettia will let you know if it's unhappy by dropping its leaves. This can happen if the plant is too cold, too dry, or too stressed by draft or inconsistent temperatures (such as by a door or in front of a vent). If you're planning to put your poinsettia outside for a few hours in suitable temperatures (above 50 degrees), watering it beforehand will give it a bit more protection from the cold.