Poinsettia gets all the votes at Christmas, since red and green match the colors of the party! After the season is over, one question remains: how can you get it to turn red?
Poinsettia, or “Christmas star”, invades garden stores from now until the end of the year. Its appeal lies in the famous colored bracts that surround its tiny flowers.
The challenge? Make your poinsettia turn red again year after year!
Colored leaves appear during days with short daylight hours. This means it needs less sunlight and more darkness.
It takes 2 months for these new red leaves to form, so plan ahead:
1/ Start the poinsettia’s “sunlight diet” in early autumn (mid or end).
2/ Keep rationing light through mid-autumn and late autumn.
3/ It’ll get red leaves around Christmas and New Years.
For maximum color on new leaves, make sure your poinsettia gets 14 to 15 hours of complete darkness every day.
Stick to the routine day in and day out, ideally always at the same time of day. You’re imitating the continuous, long winter nights from its native Mexico wilderness.
Practically, you’ve got two ways to get this done:
During this “light diet”, try to keep cooler temperatures during the nighttime, around 60 to 65°F (15 to 18°C). Water normally: this is still a growth phase for the plant. It isn’t yet dormant and needs regular watering.
Once the eight weeks are over, no need to control its light intake anymore. And it will flower again – most certainly! – at Christmas.
Getting the bracts to colour again is a twelve-month routine rather than a Christmas trick. The table below sets out what the plant needs at each stage, and why.
| Period | What to do | Watering | Aim |
|---|---|---|---|
| midwinter to late winter | Move it to a cool but very bright room | Regularly, not too much, until spring | Rest after the bracts fade |
| early spring to end of spring | Keep the soil dry for a full month | Stop watering | Trigger leaf fall and dormancy |
| late spring | Cut stems back to 4 inches (10 cm), warmer spot, may go outdoors | Start watering again, plus fertiliser | Trigger a new flush of leaves |
| Mid/end early autumn to late autumn | 14 to 15 hours of complete darkness every day | Water normally | Colour the new bracts for Christmas |
Each stage sets up the next, so the early autumn light rationing starts on a plant that is already in growth.
Not all poinsettias colour up the same way: bract shape and shade vary a great deal from one cultivar to the next, and so does the size of plant you end up with on the table. Here are the ones most often found on garden centre and supermarket benches.
| Variety | Bract colour | Bract form | Habit |
|---|---|---|---|
| Winter Rose Dark Red | Deep dark red | Curled, rose-like | Short, tight, slow growing |
| Prestige Red | True bright red | Broad, flat, overlapping | Strong stems, well branched |
| Freedom Red | Classic scarlet | Large, rounded | Compact, dense |
| Ice Punch | Red with white centre marbling | Pointed, slightly cupped | Upright, medium sized |
Poinsettia grows in the wild in Mexico where it easily reaches six feet (two meters) tall. In temperate climates, it grows much smaller, making it ideal for decorating tables.
→ Red is most common, but some are pink, salmon orange, yellow,cream,white,mottled… They all have bright green leaves as a backdrop.
Too often, poinsettia has a sad fate once the party is over… and ends up in the trash (or, slightly better, the compost pile…)!
After the blooming, simply place it in a cool room and give it water at regular intervals. At the end of spring, reduce watering. When leaves start falling off, the plant is entering its dormant phase. As this occurs, let the soil dry up completely for a month. At the end of this phase, cut it back quite short, back to 4 inches (10 cm), and water to trigger a new vegetation phase. Place it in a warm spot.
Poinsettia appreciates surrounding temperature between 60 and 74°F (15 and 23°C) while avoiding hot, dry air and drafts. Proper moisture must be ensured (immerse the pot in water at room temperature, then drip excess water out without ever letting water accumulate in the saucer). Also give it a lot of light. You can bring the plant outdoors between late spring and early autumn and feed it fertilizer over the summer.
→ Gardening: poinsettia care
