Poinsettias naturally grow as a shrub or small tree in tropical environments. However, can they thrive in areas with a milder climate? While the fluctuating temperatures in most parts of North America may not be ideal for year-round outdoor growth, with some gardening knowledge and attention to temperature changes, you can successfully cultivate poinsettias outside during the summer months. Here is a comprehensive guide on how to grow poinsettias outdoors:
1. Prep for a Color Transition:
During the winter, poinsettias develop the vibrant leaves they are known for due to longer nights. As daylight hours increase, these colorful leaves gradually turn green. While the green foliage remains throughout spring to fall, poinsettias can still be grown indoors as houseplants. Place them in a well-lit area away from direct sunlight and regularly water and fertilize them. Pruning the foliage can help maintain a compact plant.
2. Summer Getaway:
Once nighttime temperatures consistently stay above 55°F, it’s time to take your poinsettia outside for a summer retreat. Treat this outdoor period as a vacation for your plant, positioning it in a suitable outdoor location like a patio or sunny porch before bringing it back indoors around Labor Day.
3. Container Growing:
When relocating your poinsettia outside, ensure it remains in a container rather than planting it in the ground. This prevents the stress of transitioning from ground to container when moving it back indoors. If the plant outgrows its pot, repot it into a larger container with fresh potting soil.
4. Gradual Sun Exposure:
Acclimatize your poinsettia to outdoor sunlight by starting it in partial shade for a few weeks before gradually transitioning to full sun exposure. Protect the plant from strong winds as poinsettia stems are fragile.
5. Adequate Watering:
Outdoor potted plants dry out faster than indoor ones, especially in hot and windy conditions. Water your poinsettia daily during dry spells, making sure the soil remains moist but not waterlogged to prevent wilting and leaf damage.
6. Fertilizer Boost:
During the active growth phase in summer, provide your poinsettia with essential nutrients by fertilizing every two weeks. Dilute the fertilizer when transitioning back indoors in September.
7. Pruning Tips:
To maintain a compact and manageable size, trim back long stems by half during the summer. This not only enhances the plant’s appearance but also encourages lateral growth.
Developing numerous side branches is crucial to achieving a lush and full appearance for your poinsettia plants. To encourage this growth, it is recommended to provide a friendly pinch by trimming a couple of inches off the top of the poinsettia stems. This trimming process stimulates the development of leaves along the stem, resulting in a bushier plant. Horticulturists often refer to this top growth trimming technique as pinching. For optimal results, pinch the poinsettia stems every few weeks from June to August to ensure a vibrant and colorful display during the holiday season.
As the summer transitions into fall, it is essential to monitor the temperature if you are cultivating poinsettias outdoors. These plants are sensitive to frost, and even a slight touch of frost can lead to blackened leaves and damaged stems. To safeguard your poinsettia, it is advisable to bring the plant indoors well before the onset of frost. A prudent approach is to aim for Labor Day as the deadline for relocating your plant indoors, providing it with adequate time to adjust to indoor growing conditions.
Ensuring that poinsettias receive a minimum of 13 hours of complete darkness daily is crucial for triggering the color change in their leaves. During the remaining 11 hours of the day, bright sunlight is essential for promoting healthy growth. Commence the 13-hour dark period in late September to prepare your plant for displaying vibrant, color-rich leaves by Thanksgiving. Once the color transformation is evident, the prolonged darkness is no longer necessary. At this stage, you can relocate the plant to a bright window or place it under a grow light to observe the leaves fully transitioning in color.
