The flower of the Christmas season is the poinsettia, a tropical plant from Mexico that changes its leaf color when the daylength changes. Poinsettias were originally noticed for their bright red color and are now available in many colors, shapes and sizes, thanks to decades of work by plant breeders. As much as we love them, caring for poinsettias during and after the holiday can be a challenge. Here are a few tips to extend the bloom for a longer period and encourage it to grow for the months to come!
- Provide plenty of sunlight. A sunny window facing south is ideal. Be careful to not let the leaves touch the glass. Keep temperatures around 55-60F at night and 65-70F during the day.
- Keep soil slightly moist on the surface. Wait until the surface feels dry before watering, then add just enough to soak in. If water collects below the pot, pour it out. Those decorative wrappers make it hard to tell, so be sure to check. However, don’t wait for wilting before watering as that is too dry. Both overwatering and underwatering can lead to wilting and excessive leaf drop. Check the soil each day.
- Don’t fertilize while “blooming”. While the colored parts of poinsettias are actually modified leaves called bracts and the true flowers are the tiny yellow centers, we often refer to the entire non-green portion as a bloom. The plant can maintain its nutritional needs throughout the flowering time without additional fertilizer.
- In the spring, cut the plant back, fertilize and move outside. Remember, poinsettias require temperatures to always stay above 60F. If we receive any cool nights, bring it in for the night. Let the rootball become quite dry throughout April. You may have to move it under a cover if the April showers are occurring every few days.
If you want to try your luck at re-blooming, re-pot it in a slightly larger container and cut it back to about 4” high in mid-May. Keep it in nearly full sun. A little shading in the heat of the day is helpful. Water consistently and fertilize every two weeks with a water-soluble, complete fertilizer. As it grows, you will need to pinch the plant back every six weeks or so until October, I usually remove about half of the stem that has grown out. To get coloration in time for Christmas, find something dark to cover the plant or move it to a dark location each day. The poinsettia must be in complete darkness from 5 p.m. to 8 a.m. until the leaves start to turn color, usually 10 weeks. That means moving or covering and uncovering at the same time every day. Any deviation will delay the color change. Once you see a complete set of leaves coloring, the plant can be exposed to regular daylengths. If this sounds like too much work, spent poinsettias do make good compost and garden centers will be happy to sell you a new one!
Remember, poinsettia sap does contain a latex-like chemical that can cause allergic reactions. Small animals, young children, and adults with allergies should not handle poinsettias. If eaten, get medical attention immediately.