Plants by Post

Plant Profile - Poinsettia

Plant Profile - Poinsettia

‘Tis the season for….Poinsettias! 

These brightly colored plants are native to Central America, and have been cultivated in the US since the mid 1800’s. The Ecke family began growing and promoting the plants in the 1920’s, and they really gained a foothold in American Christmas decorations in the 1960’s. Now they are cultivated worldwide, and are available in many more colors including white, pink, gold, variegated, and speckled. There is a color to fit everyone’s Christmas décor. 

The question then becomes: How do you keep your indoor poinsettias looking nice for the whole holiday season?

Poinsettias are actually low maintenance plants, there are just a few things they are very particular about -- water and temperature.

Poinsettias tolerate a wide range of temperatures. Room temperature is a fine temperature for poinsettias, but they are picky about drafts of either warm or cold air. When choosing where to place your poinsettias, try to avoid placing them near forced heater vents, fireplaces (when in use), or doors that are often opened to the outside. If you have problems with drafts, you might find your poinsettia stresses out and drops most of its leaves. If that happens, you won’t be able to bring it back before the holiday. 

Poinsettias also prefer warmer days and cooler nights. Most people keep their heating system set up this way anyway, but if you keep your house very warm around the clock, you might run into dropped leaves as well. If this is your situation, you may want to consider putting them near a window so the plant can get a little nighttime coolness. 

Poinsettias are in the genus Euphorbia which means it is a succulent. They look lush with all those leaves, but they actually don’t need a ton of water. Feel the top layer of soil with your fingers. It should be just slightly moist, but not sopping. You can achieve this by giving a little bit of water frequently. Or providing a deep watering, and then letting it dry down. If you go this route, make sure to remove the plant from any saucers, or wrappers that are keeping the water from draining. You want to let any excess water drain away from the plant. 

If your plant stays too dry (dirt starts to crack and peel away from the pot) or too wet (dark soil that is glistening wet), it will stress out and drop leaves. In the case of too wet, it might also develop fungal diseases. Avoid these problems by watering only when it is needed, and avoid getting water on the leaves. 

Besides water and temperature, there are a few more things you can do to optimize your poinsettias.

When purchasing poinsettias, look for plants with closed cyathia -- the little yellow flowers in the center of the poinsettia. Look for little yellow balls that are just starting to open. If they are already open in the store, the plants are a bit older and won’t look nice as long. If you’re buying a plant the week before your holiday event, this will be fine. If you’re buying a plant on Black Friday, you want it to last a long time and this becomes more important. 

Remove the outer plastic sleeve when you get home. Many plants are shipped into stores with a decorative pot cover and a plastic sleeve to protect the bracts during shipping. Remove the plastic sleeve as soon as possible to let the leaves unfurl and breathe. Keep the decorative wrap on if you’d like, but make sure it isn’t bulging with trapped water after you irrigate.

It is also best to keep poinsettias away from small children and pets. When broken, the leaves will secrete a sticky white substance. This juice is actually natural latex. The plants are not as toxic as they are rumored to be. However, if ingested, they can cause irritation to the mouth and throat, as well as vomiting. Therefore, it is still best to keep away from any creatures that might take a bite. 

Now, what about after Christmas, what do you do then?

Many people just throw them away, but if you don’t want to, you don’t have to. They are perennials and will continue to grow if cared for properly. In fact, in frost free climates they can be planted outdoors and will grow into small trees/shrubs. In colder climates, they need to be kept indoors. 

After Christmas, you can ease up on the watering. Gradually let them dry down most of the way, but don't stop watering them altogether. By the end of January, they will drop most of their leaves and the stems will still be green. At this point, they only need a few tablespoons of water periodically. Put them away in a cool, but not freezing, area. A garage or basement works well. No need to light them at all. They have gone dormant at this point. Let them sit in that cool environment until the beginning of April, continuing to give them a few tablespoons of water every couple of weeks. 

Come April, take them out of dormancy. Put them back in the indoor light. Prune back the stems a bit to encourage new growth. Gradually increase the water. You should notice new growth very soon. Once the leaves expand, give it a little house plant fertilizer with a good micronutrient package. Repot it if you feel inclined after it is fully awake and able to tolerate the stress of transplant. Your plant should thrive all summer as a very green poinsettia.

Here is the tricky part with keeping poinsettias -- getting them to color out again.

This requires some dedication.

They are day-length sensitive, so in order to for them to turn colors again, they need to be under short days. In most areas, this means following the cues of the sun. If it is dark outside, your poinsettia should be dark as well. If the poinsettia experiences any light from your house, or even a street light, it won’t turn colors and will remain green. 

This is hard to do in modern society where we light our houses after dark. The best way I’ve found to achieve this is to cover the plant in a large over turned cardboard box. Use thick, opaque tape to cover all the seams. Gently put the box over the plant every day in the evening when you get home from work (same time on weekends). Take it off again every morning. If you successfully keep all light away from it overnight, you will get a beautifully colorful poinsettia again in time for Christmas.

It’s up to you to decide if you want to keep poinsettias for just a few weeks, or decide to add them to your permanent houseplant collection. Either way, they bring the perfect amount of holiday cheer to plant lovers and Christmas lovers alike.