All About Poinsettias: What You Need to Know to Grow Them Indoors and Outside

Written by Susan B.

When we think of holiday plants and flowers, Poinsettias are probably the first that comes to mind. And these colorful holiday beauties can be grown as houseplants long after the holiday season ends. They can also be grown in the garden in our mild Southern California climate. 

Interesting and Fun Poinsettia Facts

Poinsettia plants are named after the famous amateur botanist and statesman, John Poinsett. Poinsett, who lived from 1779 to 1851, was the first to bring  Poinsettia plants into the United States from Mexico, which he did in 1825. He served as the U.S. Ambassador to Mexico back then. Poinsettias are tropical plants that grow in the wild, growing as big as ten feet tall.

Poinsettias belong to the Euphorbia (or Spurge) family. The plant’s botanical name is Euphorbia pulcherrima. Contrary to the widespread belief that Poinsettias are poisonous, they aren’t. However, exposure to large amounts of the milky sap in their stems may irritate the skin. Pets who eat the plant may get an upset stomach, but other than those adverse effects, these plants are considered non-toxic. 

The bright cream, pink, red, white petal-like parts of Poinsettia plants aren’t the flower. They are called leaf bracts. The yellow dot-like substance in the center of these plants is really a lot of tiny flowers. 

What You Should Look For When You Go to Buy a Poinsettia Plant

Look for plants that have a lot of healthy-looking fully-opened bracts. Ensure that there is no pollen on any of the bracts because its presence signifies that the plant is nearing the end of its blooming cycle. The best plants should be at least 2 ½ times larger than the pot’s diameter. If you want to leave the foil or decorative paper on your plant’s pot for a more festive display, be sure to poke holes into the bottom to prevent your plant from sitting in water. 

Growing Poinsettias Indoors

Poinsettias are tropical plants, and they require warm temperatures, lots of light, and an abundance of humidity. 

Light: Give your Poinsettia plant a minimum of six hours of bright but indirect light every day. Put it near a bright window, but don’t let leaf bracts touch a cold window. 

Temperature: Poinsettias don’t tolerate temperature fluctuations. The optimal temperature range for these plants is between 65 and 75 degrees F. If the plant is exposed to extreme temperature fluctuations or cold drafts, the leaf bracts will drop, and plants will look scraggly. 

Watering: To avoid overwatering your Poinsettias, only water plants when the soil feels dry. Stick your finger into the pot to see if it is damp or moist below the surface. Don’t allow plants to sit in water. If you’re growing it indoors, consider placing your pots on a pebble tray to give plants the humidity they need. You can mist leaf bracts regularly to keep them hydrated. 

Fertilizing: Never fertilizer your Poinsettia plants while they are in bloom. 

Seasonal Care Schedule

Winter – Between January and March, continue to water plants on a regular schedule – as long as they aren’t in bloom. 

Spring – Once your plants stop blooming, between March and May, allow your plants to go into a rest period. Let the rest period continue until the start of summer. Prune the plant – leaving 6-to-8-inches of stem growth. Taper off watering frequency. For now, only water your plant when the soil is  completely dry. 

Summer – During the summer months (between May and S september, ) you can transplant your Poinsettias if they are root bound. It is also the time (once new growth emerges) to start a regime of fertilizing plants every two weeks with a balanced fertilizer. To encourage your plants to send out side branches, pinch back stems. If you don’t pinch stems back, the plant will grow tall and get a leggy look. You can keep your plants outside throughout the summer – as long as the temperatures don’t drop below the mid 50’s F. 

Fall – A Poinsettia’s blooming cycle coincides with the number of hours of daylight there are. The plants need to have 12-to-15 hours of total darkness every day for 8-to-10 weeks before they can bloom. Cover your plants with a black plastic bag or cardboard box. Remove the covering to allow plants to get a minimum of 6-hours of sunlight every day.  It is critical that Poinsettia plants get at least 12 hours of complete darkness every day. Continue to water and feed your plants. 

To Get Holiday Blooms: Between November and December, as long as you’ve given your plants a minimum of 12-hours of darkness every day for 8-to-10 weeks, buds should start to emerge during this time. Once plants get buds, you can stop covering them. Continue to water them, but don’t start fertilizing the plants again until Spring. 

Growing Poinsettias in Your Southern California Garden 

Poinsettias are hardy in zones 9 through 11. They can be grown as long-lasting houseplants, and you can transplant them into the garden in frost-free areas like ours. If you’re keeping your potted Poinsettia plants indoors, keep them in sunny rooms that have a south, east, or west exposure. Ensure that the daytime temperature in the rooms where you keep your plants are between 65 and 80 degrees F. The night time temperatures in the rooms shouldn’t drop below 60 degrees F. 

Transplant your Poinsettia plants in the ground when night time temperatures don’t drop below 55 degrees F. When you’re ready to plant it in the ground, ind a site with full sun. Add lots of organic matter to the planting spot before putting your Poinsettias in the ground. Water your Poinsettias regularly, and start fertilizing them a s soon as new growth appears. Always water plants after fertilizing. 

Plants that grow in the ground will still need to have 12-to-15-hours of total darkness for eight to ten weeks, starting in early October. Use a black plastic bag or a cardboard box to cover your outdoor plants. Your Poinsettia plants must have the extended period of darkness to rebloom. You can also dig the plants up and bring them indoors so you can place them in a dark closet, garage, or basement for 8-to-10 weeks. 

We encourage you to treat your Poinsettias as you would treat any house plant or long-blooming garden plant. If you’re looking for Poinsettias to add to your holiday indoor and outdoor decorating scheme, drop by any of our stores. Our garden experts will help you choose plants or find supplies to care for your plants. 

Do you like what you see? Sign up for our weekly newsletter to get content like this every week!

CLICK HERE TO SIGN UP!