Face it. While your poinsettias may still be in picture-perfect condition, they're likely to collapse after the first of the year.
Then the easiest course of action is to toss them into the green waste. But I often feel a twinge of guilt for discarding what might be a perfectly reasonable plant.
In most parts of the country, the climate takes care of the decision. It's too darned cold in the winter or too blazing hot in the summer for poinsettias to survive.
But they will live happily in the garden here on the Central Coast, provided they receive plenty of sunlight and moist, fast-draining soil. They also need protection from wind and freezing temperatures.
By Way of Background
Poinsettias are native to tropical highlands in Mexico and Central America. Their common name honors Joel Robert Poinsett, the first U.S. ambassador to Mexico, who spotted the plants in southern Mexico and brought them to South Carolina in the early 1800s.
The basic species, Euphorbia pulcherimma, is a winter-blooming shrub that grows 6 to 10 feet tall in the wild. The 35 to 40 million potted plants sold during the holidays today share a common ancestry, but are bred and grown for smaller size, color, style and ease of shipping.
Wait Now, Plant Later
Poinsettias detest cold weather, so now is not the time to plant them. Instead, put your plants — still in their pots — in a cool, sheltered spot, such as a protected patio or garage. After the leaves drop, cut the stems down to a few inches tall. Water sparingly, keeping the soil barely damp.
When temperatures warm in spring, plant your poinsettias in full sun. Look for a spot that's out of the wind, doesn't get frosty and has excellent drainage.
Plenty of head room is important, too. In the garden, your formerly 1 to 2-foot-tall plants may stretch head-high or taller, unless you faithfully pinch back the stems every few weeks during the growing season.
If you forgo the pinching, consider planting something short in front of them, as poinsettias are often scraggly within the first few feet of ground.
After planting, spread an inch or two of mulch around each plant, then thoroughly water them in. Plan to water every week or two, or more frequently if their leaves go limp. If you opt to fertilize, apply a high-nitrogen product twice a month once the leaves begin to turn red.
As for when that happens -- the "bloom" is a result of the colored bracts, or modified leaves, responding to longer nights. Poinsettias need about 12 hours of darkness to trigger the change, with the leaves then taking several months to mature, depending on the variety, temperature and intensity of light.
If you plant your poinsettias near an all-night patio light or street light, they might not bloom until well into January. Commercial growers manipulate the light to create plants that are prematurely colored up from Thanksgiving through Christmas.
The Forcing Route
If you absolutely must have a poinsettia that stays compact and reblooms at Christmas, don't plant it in the ground.
Instead, commercial growers recommend the following.
Keep the poinsettia in its pot. When the leaves drop, cut back the stems to 6 inches tall, leaving two joints on each stem. Water when the top inch or so of soil dries out and pinch back new growth every few weeks to encourage a tighter, fuller shape.
In mid September to early October, start controlling the light.
Every night for eight to 10 weeks, move the pot into a dark closet for 14 hours. Then put it in the sun for 10 hours every day. Two months of the routine is said to produce a dense, compact plant with vivid holiday color.
As for whether the exacting regimen works, I've never had the staying power to try it, but would welcome hearing from anyone who has.