In the Garden Articles

Poinsettias

by Joan S. Bolton

They're here. Over the next month, more than 40 million potted poinsettias are expected to make their way into our homes, offices, stores, restaurants and anywhere else merry elves deem suitable for decorating.

For those of us with dirt under our fingernails, the massive annual rollout poses two challenges. The most immediate is how to keep those poinsettias looking pretty and plump through the holidays. Later on, is a graceful transition from temporary houseguest to permanent plant possible?

Indoors

Poinsettias are native to tropical highlands in Central America and Mexico. Their common name is a nod to Joel Robert Poinsett, the first U.S. ambassador to Mexico, who found the plants growing in southern Mexico and transported them to South Carolina in the early 1800s. The basic species, Euphorbia pulcherrima, is a winter-flowering shrub and grows 6 to 10 feet tall in the wild.

The potted plants we buy today share a common ancestry, but are grown and bred for smaller size, color, style and ease of shipping.

These greenhouse babies are happiest indoors with at least 6 hours of bright, indirect light; day-time temperatures 60 to 70 degrees; and night-time temperatures about 10 degrees cooler.

Their leaves may fall off if temperatures soar above 80 degrees or drop below 50 degrees. Wild swings in temperature can cause the leaves to drop, too.

Air movement is also key. Poinsettias don't like being in a wind tunnel. So keep your plants away from drafts, doors or windows that open and close frequently, and heater vents.

Water your plants when the top half inch of soil feels dry. In the wild, poinsettias thrive with humidity and fast-draining soil. If their roots are constantly wet, they're likely to develop root or crown rot. But if they stay dry for too long, their leaves will fade, curl along the edges and fall off.

Your best bet is to cut off the bottom of any decorative wrapping or punch a few holes in the bottom of the plastic or foil liner. That way, when you water, the excess will drain out. If you use a saucer, be sure to pour out any remaining water half an hour after watering. Or do like I do: soak your plants in the kitchen sink. It's extra work, but it ensures the roots won't sit in water.

Another way to tell when it's time to water is the lift test. Pick up a pot after having just watered. Feel the weight. Check it a few days later. If the pot still feels meaty, it's fine. If it feels considerably lighter, go ahead and water.

Outdoors

In most of the country, the likely trajectory of a poinsettia is straight from the house to the green waste. A few ambitious souls save their plants from year to year, going through a tedious regimen of letting the plants go dry, then storing them in shade, then fooling with their daylight exposure as time marches toward Christmas and the hope of reblooming.

On the Central Coast, we have a third option: planting poinsettias in the ground.

Cruise through an older neighborhood, and you're likely to spot lanky poinsettias poking up against an eave or silhouetted against a south-facing wall. In colder years the plants may freeze to the ground. But they should recover.

If you do try planting, wait until spring. In the meantime, put your plants -- still in their pots -- in a cool, sheltered spot, such as a protected patio or your garage. Once the leaves fall off, cut the stems down to a few inches tall. Go easy on the water. When temperatures begin to warm in the spring, plant your plants in a sunny spot that�s out of the wind, is protected from frost and has good to excellent drainage and plenty of head room. While fresh pot plants may only be a foot or two tall, most poinsettias in the garden revert to head-high or higher, unless you meticulously pinch back the stems on a regular basis.

Mulch your plants, then water occasionally. Some folks say it's not necessary to fertilize outdoor poinsettias. Others recommend applying a high-nitrogen fertilizer twice a month once the leaves begin to turn red.

Left to their own devices, poinsettias can look pretty scraggly for the first few feet out of the ground. If you don't plan to pinch back every few weeks during the growing season, plant something in front to hide their knees and ankles.

The "bloom" is a result of the colored bracts, or modified leaves, responding to long nights. Poinsettias need about 12 hours of darkness to trigger the change in color. The leaves then take 2 to 3 months to mature, depending on the variety, temperature and intensity of light.

If your poinsettias are planted near an all-night patio light or streetlight, they may not bloom until well into the new year. Commercial growers manipulate the light to create plants ready to sell from Thanksgiving through Christmas.

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The Novelties

When it comes to poinsettias, Henry Ford's oft-quoted statement that customers could buy a Model T in any color, as long as it was black, immediately comes to mind.

Despite a tempting array of pinks, purples, splotches and dots, 80 percent of the poinsettias sold are still the traditional red and green, according to Snow Maestas, marketing manager for Paul Ecke Ranch, the world�s largest breeder and supplier of poinsettias.

But that doesn't mean the breeders don't keep trying.

Ecke's 2007 catalog showcases some 70 varieties, including Polly's Pink, in hot pink, and Ice Punch, a cranberry red with white splashes. There's also Eggnog, a crinkly, rose-style poinsettia, in a creamy white. For 2008, Ecke plans to introduce Orange Spice, a pumpkin-orange poinsettia with dark green leaves.

Yet the lion's share of the poinsettia business is red, red, red.

The Ecke ranch sells poinsettia cuttings, mostly in June and July, to greenhouse growers that then "finish" the plants, growing them up and readying them for sale.

The company's most recent blockbuster is Prestige Red. The number-one seller in the nation, it has deep red coloring against dark green leaves.

Yet, Maestas noted, consumers probably haven't noticed, because it's still a traditional red. Prestige Red's qualities are more important to the growers, in that it grows in an upright v-shape, bears sturdy stems and isn't likely to get damaged in shipping.

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Are Poinsettias Deadly?

Chalk that up as an urban myth.

According to the California Poison Control System's website (www.calpoison.org), "Eating many leaves may cause mild stomach upset. The sap from the plant may cause skin rash and should be washed off with soap and water. Contrary to earlier beliefs, poinsettias are safe in the home during the holidays."

Other impressive institutions also dispel the notion, including POISINDEX, which provides poison information to poison control centers; Ohio State University; the American Society of Florists; the ASPCA Animal Poison Center in Urbana, Illinois; and the American Veterinary Medicine Association of America.

The origin of the myth may be traced back to 1919, when the 2-year-old child of a U.S. Army officer died in Hawaii. Supposedly she was found beneath a poinsettia tree, holding a poinsettia leaf. Yet another report states that the last living witness told a Cornell University professor in 1972 that poinsettias weren�t involved and that he didn't know how the story got started.

In the meantime, in the early 1970s, researchers at Ohio State University fed all parts of poinsettia plants to rats, with no ill effect. The dosage was equivalent to a 50-pound child eating more than 500 bracts, or more than a pound of the modified leaves.

By 2,000, more than 22,000 exposures had been reported to poison control centers nationwide. Researchers at Children�s Hospital of Pittsburgh and Carnegie Mellon University studied those reports and said they found no significant toxicity.

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Seeds of Wisdom

Choose the freshest poinsettia by looking at the tiny flowers in the center of the colored leaves, or bracts. If the little buds are barely showing green or red, the plant is likely to last longer than one in which yellow pollen has begun to form.