How Do I Keep Poinsettias Alive and Thriving for Next Christmas?

With exception of my pooch, Lulu, I have a difficult time keeping things alive in my house. Fortunately, horticulturalist Brad Balsis of Habersham Gardens has no shortage of advice for those of us who lack a green thumb. Here are his tips to help your poinsettias — and mine — live to see another Christmas.

Keep them cozy

Poinsettias do best when the thermostat rests between 65 and 75 degrees F (18 to 25 degrees C). "You don’t want to go much lower in the evening or you will get leaf drop," he says. "Also, keep them away from drafts and cold windows."

Poinsettias also like lots of direct light. Place your plants near a southern, eastern or western window and keep the soil moist while they are still in bloom. Balsis warns against allowing poinsettias to sit in water. Instead, gently remove the plant from its container, soak it well and place it back in the pot.

"When the surface is dry to the touch, then re-water," he says. "Don’t just do it on a schedule because of the heat going on and off."

Get snippy in the spring

Allow your poinsettias to go a little drier between watering during the spring, Balsis says. In May, cut about 4 inches from each stem to foster a lush, full plant during the winter. Spring also is the best time to start fertilizing.

Change the venue

As the temperatures rise around June, it’s time to move your poinsettias outside to an area that gets a moderate amount of sunshine. "They really don’t like hot, hot afternoon sun," Balsis says. "Even though you see them growing natively out in good sun."

Look for a spot that gets good morning sun and partially shaded afternoon sun. Poinsettias also tend to do well on a patio or under a tree. "Just protect them from full, hot sun or they dry out so fast that you have to water daily," he says.

As the fertilizer begins to do its work, you should start noticing new branches. Balsis says that’s the time to pinch another inch from each stem. Continue adding a quarter-strength fertilizer on a weekly basis or a full-strength fertilizer on a monthly basis. Also, be sure to fertilize while the soil is moist or you could burn the roots.

Watch for insects such as aphids and white flies, which tend to accumulate on the underside of leaves. Organic insecticides will help correct the problem, but be prepared to use them more frequently than heavy-duty chemical insecticides. For an easy homemade insecticide, add one teaspoon of mild dishwashing liquid to a gallon of water. Place it in a spray bottle that you keep near the plants.

Watch the temperature

When the temperature starts to dip below 65 F (18 C), those poinsettias need to come inside once again. It’s also time to cultivate that deep red bloom. "Beginning Oct. 1, make sure that plant gets a 12-hour night," Balsis says. "That’s 12 hours of uninterrupted darkness — no walking into the room and turning on a light and walking out — or you delay flowering."

Some gardeners place a cardboard box over the plant during this 12-hour bedtime. Placing plants in a dark room from 5 p.m. to 8 a.m. will do the trick. Return them to a space that gets plenty of sunshine during the day.

"It’s a bit of a thing," Balsis admits, "but you only do it for about eight weeks. That’s key to getting them to bloom on time."

Once your poinsettias have bloomed, you don’t need to add fertilizer. Just keep watering as you did this Christmas. If the plant is located near a heater, be prepared to water more frequently.

"Then, you start all over again; it’s fun," Balsis says.

I plan to follow his tips to the letter. Hopefully, we will have some gorgeous plants this time next year.