Tips to Get Your Poinsettia to Bloom

By Matt‌ ‌Gibson‌

Every year around the end of November or the beginning of December, Poinsettias start flying off the shelves, literally. In the United States alone, 35 million poinsettias in containers are brought into American homes to bring in some holiday cheer, the vast majority of which are purchased during the holiday season. Unfortunately, every new year, during the first few weeks of January, nearly 35 million poinsettias are tossed in the garbage and forgotten until next year, when the holidays begin approaching.

Though it does take a bit of extra effort and attention, poinsettias can be kept alive throughout the year, and even coerced into re-blooming during the holidays. Poinsettias are perennial plants, and if provided with the appropriate growing environment and regular care, they can live quite a long time, and if they are given enough room, they can even grow into massive bushes, reaching heights of ten to 15 feet. Imagine the kind of holiday cheer a 15 foot poinsettia bush can bring when its outer bracts turn bright, Rudolph the reindeer-nose red.

Poinsettias are the subject of an excellent legend which ties them to the Christmas season, aside from their red and green hues. According to the tale, a young child from a poor family, who had no money to buy a gift, gathered a basket full of weeds from the fields and brought them into the local church in order to decorate the altar on Christmas eve. As the congregation looked on in astonishment, the weeds transformed before their very eyes, into an awe-inspiring, colorful display of green and red flowers.

Poinsettia’s origin story has one minor flaw, however. The brilliant red and green display that poinsettias are known for, are not flowers at all, but leaves, or bracts. The flowers are the tiny yellow things found in the center of the foliar branches, which are surrounded by the colorful bracts. After the holiday season, the color of the bracts start to fade and, due to the poor growing environment caused by the way most poinsettias are packaged, the plants start to look sick. Their noticeable deterioration causes most people to believe they are dead or dying, which is why so many Poinsettias are tossed out in the trash each January.

If given a new pot and fresh potting soil, your poinsettias will bounce back rather quickly, and though they won’t be as colorful, poinsettias still make an attractive houseplant when their bracts are less vibrantly colored. When the holiday season rolls around again, you won’t have to fork out cash for purchasing new poinsettias, because you wisely chose to keep yours around. Getting your poinsettias to produce their brilliant holiday colors again is a little bit tricky, but once you know how to do it, the success rate is actually very high.

With just a little bit of extra attention, you can turn last year’s poinsettia into this year’s holiday centerpiece. And since you gave your poinsettia a new home in a larger pot nearly a year ago, it will be significantly larger this time around. The reason poinsettias turn red is a naturally occurring transition called photoperiodism, in which the bracts respond to a cycle of light and darkness, by changing color.

Not all poinsettias change from green to red, though it is the most common color transition. Some varieties have bracts that change from a deep green to a brighter or lighter green, pink, white, and a few other variations. There are a few poinsettia varieties that have variegated leaves, or leaves that continue to change color throughout the blooming period.

Reblooming your Poinsettia

The key to getting your poinsettia to turn red (or to re-shade), is the elimination of light. The color transformation of the plant’s lovely bracts occurs when the plants are given precise periods of complete darkness. Throughout the daytime, your poinsettias should be soaking up the sun. Give them as much bright light as you are able to, as light exposure is how the plants absorb the energy required to produce such vivid colors.

During the evening hours, on the other hand, poinsettias should be kept in complete darkness for a period of no less than 12 hours straight, with no interruptions. You may have to take extra measures to ensure that your plants don’t accidentally catch a glimpse of light during their dark time, such as covering the entire plant in a cardboard box, or keeping the plant in a dark closet.

Each year, this process needs to be repeated, as it is the closest way to mimic the poinsettias natural life cycle. Once the holidays end and the poinsettia’s color begins to fade, encourage your poinsettia to enter dormancy until springtime by reducing the amount of water you give it. Don’t cut off watering completely, but water lightly only when the soil around the plant has dried out entirely.

Resume regular watering provisions in March or April and provide an all-purpose houseplant fertilizer as directed on the package. Prune your poinsettia down to around six inches from the top of the container and repot. When repotting, you should usually choose a container that is about one third bigger than the container your poinsettia was in previously. However, the first time you repot your poinsettia, especially if it was kept in a tiny pot and has become rootbound, you should increase your container size to a planter that is twice as large as the dinky little plastic planter that most poinsettias are sold in.

The tiny plastic planter that poinsettias are typically sold in is far too small for poinsettias to grow in comfortably, and is likely the cause of the plant looking sick just after the holidays. Poinsettias are usually sold in tiny plastic planters that are wrapped in shiny plastic decorative wrap that makes it nearly impossible for water to drain out of the planter properly. Therefore, it’s not a bad idea to replant your poinsettia as soon as you get it home from the store. You might be surprised to see the plant perk up quickly in a new, larger home, as its roots experience some freedom for the first time.

When repotting your poinsettia, use a potting soil that is especially formulated for houseplants and provide an all-purpose houseplant fertilizer as the time of the repotting. Water well as soon as you place your poinsettia in its new home to help the soil settle in around the plant. Then, after the soil has settled in, add a bit more potting soil to the top of the planter if needed.

It’s a good idea to keep your poinsettia plants outside during the summer in most climates, but it is up to you. If you choose to move it outdoors, keep it in a protected location away from heavy winds. To promote a bushier growth habit, pinch the tips of new growth until mid-August.

When autumn comes around again and the days become shorter, cut back on feeding and bring the plant or plants back inside. As you did the year before, cut back on watering during September and October, exposing your poinsettias to bright days and complete darkness during the night. Keep your poinsettias in a humid environment during this period, but don’t mist the leaves directly, as it could cause leaf spot. Continue until you see the outer bracts displaying their distinctly vibrant coloration. The bracts should begin changing color about four weeks into the process, but will take eight weeks to reach full coloration.

Once your poinsettias are red as Santa’s suit, reduce the darkness and resume regular waterings. They should stay showy for several weeks, until just after Christmas. Around the start of January, your poinsettias will start to lose their leaves. When you notice leaves dropping, cut its stems down to four to six inches. Keep the plant warm and the soil mostly dry. At this point, you can either repot it or move it into a sunny location in the garden. Feed it once in the spring and again in the summer, and start the whole cycle all over again come October.

Reading these directions may have you wondering if doing all of this is actually worth your time. But once you are used to the cycle, it’s really not as much work as it sounds. The reward for all of your hard work is not just about the small amount of money you save each year on poinsettias. The real reward is seeing your poinsettias grow to impressively large sizes. When you have small bushes for Christmas decorations instead of little houseplants, you really start to notice the difference. Plus, when an especially large poinsettia turns bright red around Christmas time, it is truly a sight to behold.