Poinsettias are a popular holiday plant known for their bright red and green foliage. While they are a festive addition to indoor décor during the winter months, many wonder if these plants can survive outdoors in colder climates. Here is a detailed look at whether poinsettias can live outside in winter.
Can Poinsettias Tolerate Cold Temperatures?
Poinsettias are native to Mexico, where temperatures rarely drop below 50 degrees Fahrenheit. As a result, they are not well-equipped to handle freezing winter weather. Poinsettias are sensitive to temperatures below 50 degrees Fahrenheit. Exposing the plants to frost or freezing temperatures, even for short periods, can damage or kill them. Their roots are especially vulnerable to cold injury.
While mature poinsettia plants can tolerate temperatures down into the mid-40s Fahrenheit for short periods, anything colder can result in stunted growth, bract damage, and potentially death. Even cool temperatures above freezing can cause the colorful bracts to fade and wilt prematurely.
So in most regions with cold winters, poinsettias cannot survive sustained freezing temperatures or frost outdoors without protection. Gardeners in USDA Hardiness Zones 8-11 may have better luck keeping poinsettias outside during winter, but gardeners in colder zones will need to bring them indoors or take steps to protect them from the elements.
Protecting Poinsettias in Winter Gardens
For gardeners who want to experiment with overwintering poinsettias outdoors, there are a few techniques that may help the plants survive:
- Choose sheltered locations – Site poinsettias next to the house foundation or under tree canopies where they can be protected from winds and receive radiant heat from the home’s walls.
- Cover the plants – Place poinsettias in a cold frame or unheated greenhouse to shield them from precipitation and keep surrounding air temperatures slightly warmer.
- Mulch heavily – Apply a deep organic mulch of shredded leaves, pine needles, or bark around the base of poinsettias to insulate plant roots and retain soil heat.
- Wrap or cover bracts – To protect colorful bracts from fading, carefully wrap them with a breathable fabric or place the entire plant under a frost cloth temporarily during cold snaps.
- Plant in containers – Growing poinsettias in containers allows you to move them to protected areas as needed on short notice.
While these measures may enable you to keep poinsettias outside longer into autumn and early winter, they will typically still need to be moved indoors or to a heated greenhouse to avoid damage once temperatures drop below freezing.
Caring for Poinsettias Indoors in Winter
Since poinsettias cannot withstand harsh winter conditions outdoors year-round in most climates, they are best enjoyed as houseplants during the cooler months. Here are some tips for providing the right growing conditions indoors:
- Place poinsettias in a warm, sunny window where they will receive at least 4-6 hours of direct sunlight daily. Southern exposure is ideal.
- Water whenever the top 1-2 inches of soil become dry, taking care not to overwater. The holiday season’s low light and humidity can make proper watering tricky.
- Ideal indoor temperatures for poinsettias are between 60-70°F during the day and around 55°F at night. Avoid excessive heat or cold drafts.
- Use room humidifiers or pebble trays to increase humidity around the plants to 40-50%. Low humidity can cause leaf drop.
- Apply a balanced, water-soluble fertilizer every 2-3 weeks while plants are actively growing and bracts are still colorful.
- Prune back plants as needed to control leggy growth and maintain a compact shape. Cut back stems to just above leaf nodes.
- Monitor for common pests like whiteflies, spider mites, and mealybugs which thrive indoors. Treat infestations early before they get out of control.
With the right indoor growing conditions, poinsettias can retain their holiday brilliance for months, often until spring in colder zones. Once bracts fade, allow the plants to rest before placing them outside again after the danger of frost has passed.
Key Takeaways on Outdoor Care
To summarize the key points on whether poinsettias can spend the winter outdoors:
- Poinsettias are tropical plants that can only survive outdoors in frost-free climates. They suffer serious damage when exposed to temperatures below 50°F.
- Gardeners in zones 8-11 may be able to keep poinsettias outside over winter if carefully sited and protected from cold extremes.
- Sheltering, covering, and heavily mulching plants can help marginally improve their cold tolerance. But potted plants must be moved indoors before freezing temps arrive.
- Indoors, provide poinsettias with ample sunlight, consistent water, humidity, warm temperatures, and fertilization to maintain their holiday beauty during winter.
- Once their bracts fade, poinsettias enter a dormant period best suited to cool, dark conditions indoors. They can be moved back outside after all danger of frost is past.
With special care and protection from the elements, it may be possible to overwinter poinsettia plants outdoors in some warmer climates. But in general, these delicate tropicals plants fare best as temporary indoor decorations during the winter months in most regions. By following good cultural practices indoors and understanding their cold sensitivity, gardeners can continue enjoying poinsettias throughout the holiday season and beyond.
Frequently Asked Questions
Can poinsettias stay outside in winter in pots?
Poinsettias in containers can be kept outdoors over winter only in frost-free climates. Elsewhere, potted poinsettias should be brought indoors or under cover before temperatures drop below 50°F. Their roots are particularly vulnerable to cold damage.
How cold hardy are poinsettias?
Poinsettias are only marginally cold hardy, tolerating brief exposure to temperatures down to 40-45°F before sustaining damage. Hard frosts or freezing temperatures, even for short periods, will kill unprotected poinsettia plants.
Should you cut back poinsettias after Christmas?
Yes, poinsettias should be pruned back around early spring once their bracts fade. Cut stems back to 4-6 inches above soil level to encourage bushy regrowth. Keep watering and fertilizing lightly until warm weather returns.
What zone can you grow poinsettias outside?
Poinsettias can be grown outside year-round in zones 8-11. In zones 7 and warmer, they can be kept outdoors over winter if sheltered from cold and frost. Anywhere colder, they should be brought indoors or undercover during the winter months.
Do poinsettias come back every year?
With proper care, poinsettias can be kept from year to year and rebloom each holiday season. Grow them outdoors in summer, prune back in spring, restrict light in fall to initiate blooming, and protect from frost when moving them indoors for winter display.
Conclusion
While poinsettias make a popular Christmas plant, their tropical origins mean they cannot withstand freezing winter temperatures for long. Gardeners in frost-free climates can cultivate poinsettias year-round outdoors with ease. But those in colder zones will need to either enjoy poinsettias as temporary houseplants or take special precautions to shield plants from winter extremes if attempting to keep them outside. With attention to their sensitivity to cold, protection from the elements, and ideal indoor care, poinsettias can thrive as a recurring holiday delight both indoors and out.