In equatorial zones, poinsettias grow like weeds. But a touch of our winter is killing. How these tropical natives have become the flower of Christmas is a story of careful science in the greenhouse and ingenuity in marketing.
“Most mother plants are grown offshore, in Nicaragua, Costa Rica or Kenya,” says Ray Greenstreet, whose Greenstreet Gardens is a major grower for our homes and for wholesalers.
In June and July, Greenstreet and other growers bring in cuttings and root them in greenhouses. By late July and early August, plants are transplanted into display pots.
The length of day light controls the plant’s growth and coloring. Flower buds form only when daylight is less than 12 hours.
“In the long days of summer, we want to keep them vegetative as they grow to a certain size,” Greenstreet explains. “Then about September 23, days get shorter than nights, which naturally initiates blooming.”
Traditionally, light and shade were controlled in greenhouses so plants bloomed sequentially. In the last quarter century, plants have been bred for seasonal blooming.
“Early-season poinsettias bloom around November 15,” Greenstreet says, “and others bloom as late as mid-December. We grow a number of different bloom-response times, so we have nice fresh plants through the season.”
For shipping around the country, Greenstreet roots about 185 varieties, in colors ranging from whites to mauves and lots of reds.
“Right before 9/11,” Greenstreet says, “mauve or pink were selling well.” After the terrorist attacks, he continued, “people went back to tradition, and all they wanted for a couple seasons was red or white.”
Now, variety is back. At Greenstreet you can choose from some 80 varieties, differing in leaf form as well as color.
Buy your poinsettia when the temperature is above 36 degrees, packaged in a sleeve. Keep it warm in the car and bringing it in. At home, keep it away from drafts at a temperature between 60 and 70 degrees, in average light and evenly moist. Don’t let it sit in water. Carry it to a sink for watering, and let it drain before you put it back on display.
Finally, don’t worry if your baby or cat has a bite. Poinsettias don’t taste good but are not toxic, both Greenstreet and Bay Gardener Frank Gouin confirm.