BOISE, Idaho — On this special 'You Can Grow It', Garden Master Jim Duthie tells us about these fascinating and beautiful plants, and shows us how they magically transform into all of their brilliant colors, just in time for the holidays.
They don't grow wild around here, or even in landscaped yards and gardens. But one look at these brightly colored blossoms, and you know it's the holiday season.
Poinsettias are an iconic symbol of Christmas. but have you ever wondered where they come from, and how they get from a green plant to these colorful beauties?
Poinsettias are native to Mexico, and were unknown in the U.S. until 1828, when an American named Joel Poinsett, a botanist who was serving as the U.S. Ambassador to Mexico, ran across them growing wild. There, they were known as the 'Flor de Nochabuena', or the Christmas Eve flower. Poinsett sent samples back to the U.S., where they soon became known as poinsettias in his honor.
Poinsettias thrive outdoors in warmer climates, even in some parts of the U.S., including Hawaii, Florida, and parts of the southwest, and can grow into large shrubs up to 15 feet high. However, while Idaho's climate is too cold for poinsettias to grow outdoors year-round, inside Edwards Greenhouses in Boise, conditions are ideal.
Starting in June, Poinsettia cuttings, called plugs, are set out in the greenhouse to be watered and fertilized. They'll continue to grow to various sizes, depending on the size of their containers.
The Poinsettia's color change is triggered by the length of daylight, just like outdoor trees and shrubs. The plants need about 14 hours of continuous darkness to initiate their color change.
So for weeks the plants stay green. Around late Oct., a subtle change begins to occur, with a hint of red showing up in the leaves. By mid-November, the full change is underway, and all of the various colors and patterns have begun to emerge.
What we think of as flowers, the part that changes color, are actually colored leaves, called bracts. The plants continue to grow more brilliant each day, until they're ready for you to enjoy in your holiday displays.
Poinsettias come in nearly 100 different colors, shades and shapes. Here at Edwards, there are nearly three dozen varieties, including 10 to 15 different shades of red, as well as pink, white, mauve, salmon and yellow shades. There are even some mottled and variegated varieties known as novelties.
Classic red is the most popular, and are used in the beautiful annual Capitol Poinsettia tree in the center of the Idaho State Capitol rotunda, an Edwards tradition for nearly 40 years.
The colorful transformation of the poinsettia is truly magical, making it an iconic symbol of a magical time of year.
To keep your Poinsettias looking good through the holidays, put them in a somewhat cool location, with bright, indirect sunlight, away from heater vents and drafts. Keep the soil moist, watering every few days, but don't overwater, and make sure they have proper drainage.
Once spring arrives, and nighttime temperatures stay above 50 degrees, you can move your Poinsettia outside for the summer.
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