Post-Holiday Poinsettia Practices

NanSterman

The holidays are past, and all the decorations put away. What will you do with your poinsettias? Plant them, of course!

Poinsettias’ botanical name is Euphorbia pulcherrima. They are native to tropical forests of Mexico and Central America where they grow ten or twelve feet tall and wide. What look like poinsettia flowers are actually bright colored bracts. The true flowers are tiny, yellow, and sit in the very center of the bracts. The bracts, though, are what make poinsettias so beautiful, and are also what breeders tinker with to create different colors and patterns.

While the wild plants have been tamed somewhat, potted poinsettias are not intended to be houseplants long term. So, keeping potted poinsettias going through the holidays can be a challenge. Your poinsettias will do best in a spot with bright light, where temperatures stay around 65 degrees day and night.

Drainage is critical, in fact, most poinsettias succumb to overwatering – they literally drown. So, remove the fancy foil wrapper as soon as you bring the plant into your house. If you put a plate or bowl beneath the pot to catch excess water, prop the pot up on gravel or on pot feet so the poinsettia does not sit in water. When you water, take the pot to the sink and let the water run into it slowly, until it saturates the soil and starts to drip out the bottom. Wait for the surface to dry out before watering again.

Once the holidays are over, do not throw your poinsettias away; plant them in your garden instead. If you live along the coast, plant just after the New Year. Inland, keep poinsettias indoors in their pots after the last frost in spring, then plant.

Your poinsettias will bloom again, in the ground, if they are planted in a spot that gets total nighttime darkness from September to December. How much light they get during the day is not nearly as important as the darkness they get overnight. If there is a security light nearby or a streetlight, a bright window, or just twinkly lights, the plants will grow but the showy bracts will stay green, rather than turn red or pink or even gold.

Plant your poinsettias in soil that drains well, so the roots do not stay wet – just like in pot. Do not be surprised if they drop all their leaves right after you plant them. Be patient while they recover from transplant shock.

Once the days warm up past 60 degrees, your poinsettias will sprout new growth. At that point, give them some all-purpose organic fertilizer and continue to fertilize through the growing season, following the directions on the label.

If you like big, rangy poinsettias, do not bother pruning. But if you prefer a more compact, bushier plant, prune according to the holidays. Prune the branches back by as much as half on Memorial Day. Do the same thing on the Fourth of July and again on Labor Day. Shape the plant as you prune. New flower buds start to form after Labor Day, so do not prune them again or you will cut off the buds.

By the way, poinsettias were long thought to be toxic, but that has proven to be an urban myth. Like other members of the Euphorbia family, they do have a white milky sap that can irritate skin and damage eyes. That said, as you enjoy your potted poinsettia on the dining room table, it is best to wash your hands if a branch breaks off and the white sap drips onto your skin.

And if you already threw your poinsettias away, at least you have an idea for this year’s holiday season!

Garden expert, designer, educator, and author Nan Sterman specializes in low water, sustainable, and edible landscapes. Nan hosts, co-writes, and co-produces opens in a new windowA Growing Passion, a show that explores the power of plants in our world. Nan is also author of California Gardener’s Guide vII, Waterwise Plants for the Southwest, and Hot Colors, Dry Garden. More information is at opens in a new windowwaterwisegardener.com.