Plant of the Week: What Else but Poinsettias!
Everyone loves the cheer this holiday plant brings to its surroundings, yet there’s so much yet to learn. Here are some of the fun facts about poinsettias.
Poinsettias are native to Mexico, while most other cultivated euphorbias are from the eastern hemisphere – and many of those plants look more like cacti. Examples: pencil plant, crown-of-thorns and baseball cactus. All are sisters to poinsettias.
Poinsettias are not poisonous! That’s based on research done at Ohio State 41 years ago. (Good news apparently travels slowly.) While their latex sap might irritate some people’s eyes and skin, the plants are not toxic.
Poinsettias measure the length of the dark period (night). The flower-inducing hormone they produce in their growing tips is destroyed by light. Only when they’re given 14 hours of uninterrupted darkness will enough of the hormone stay in place to allow them to develop their flowers.
Poinsettias prefer full sunlight in daytime and 14 hours of darkness at night. They’re either produced away from ambient light sources at night (street and security lights, overhead greenhouse lights, etc.), or black shade fabric is pulled over them to shield them.
All poinsettia flowers are the same color. Most folks would think they were red, while some would meander off into the whites, pinks and marbled colors. Those are floral bracts, which means they are modified leaves. Look closely at a plant, and you’ll see how the colorful foliage gradually changes shape as the new leaves are formed. Oh, and all poinsettia flowers are yellow.
Thinking about saving your poinsettia and reblooming it next year? Keep in mind that poinsettias mature very quickly in greenhouse conditions. The lovely plants we’re enjoying right now were tiny unrooted cuttings just three months ago. In fact, the large stock plants that were mothers to the plants we’re buying and giving now, were themselves simple unrooted cuttings last spring. That plant you’re enjoying right now, if grown in a tropical setting, could be 10 feet tall and wide in 12 months!