Poinsettia Care: How to Grow Poinsettias Indoors and Outdoors

Written by Susan B.

When we picture holiday plants, the poinsettia is usually the first that comes to mind. But these colorful beauties are far more than a one-season decoration: they make long-lived houseplants, and in our mild Southern California climate you can even grow them outdoors in the garden. Here is how to keep a poinsettia healthy indoors, how to move it outside, and how to get it to color up again next year.

What Is a Poinsettia?

The poinsettia (Euphorbia pulcherrima) is a member of the Euphorbia, or spurge, family, and it is native to Mexico, where it grows into large woody shrubs that often reach 10 feet tall (University of Illinois Extension). The bright red, pink, cream, or white “petals” everyone admires are not flowers at all: they are modified leaves called bracts, and the true flowers are the small greenish-yellow structures (cyathia) clustered in the center. The plant is named for John Poinsett, the amateur botanist and U.S. Ambassador to Mexico who first brought it to the United States in 1825.

Are Poinsettias Indoor or Outdoor Plants?

Both. A poinsettia is most often grown as a winter houseplant, and it will happily live indoors long after the holidays. But because it is a tropical plant, it can also go outdoors in a frost-free climate like Southern California. Indoors it needs bright, indirect light; outdoors it needs full sun and protection from frost. So the honest answer is that a poinsettia is a tropical plant you can enjoy either way, depending on your weather.

How to Care for a Poinsettia Indoors

Poinsettias are not fussy, but they do have preferences. Here is what they want (University of Illinois Extension, University of Minnesota Extension):

Need	What poinsettias want
Light	About 6 hours of bright, indirect light a day indoors; full sun outdoors
Temperature	65 to 75 F by day; no colder than about 55 F at night, and protect from anything below 50 F
Water	When the soil surface feels dry; never let the pot sit in water
Humidity	Moderate; a pebble tray helps indoors in dry winter air
Fertilizer	None while in bloom; every 2 weeks during spring and summer growth
Hardiness	USDA zones 9 to 11 (frost-tender; grow outdoors only in frost-free areas)

Light. Give your poinsettia at least six hours of bright, indirect light a day near a sunny window, but do not let the bracts press against cold glass. Temperature. The plants dislike swings and drafts; keep them between 65 and 75 degrees during the day and no colder than about 55 degrees at night, and keep them away from heating vents, fireplaces, and cold doorways. Exposure below about 50 degrees will damage the plant. Water. Water only when the soil surface feels dry, let the excess drain, and never leave the pot standing in water. If you keep the decorative foil on the pot, poke holes in the bottom so water can escape. Humidity. A pebble tray under the pot adds the humidity these tropical plants like in winter. Fertilizer. Do not feed a poinsettia while it is in bloom.

Can You Plant Poinsettias Outside?

Yes, in a frost-free climate like most of Southern California. Poinsettias are hardy in USDA zones 9 to 11 and are frost-tender, so they will not survive a hard winter outdoors (University of Vermont Extension). Wait until the danger of frost has passed and night temperatures stay above about 55 degrees, then choose a full-sun spot, work plenty of organic matter into the soil, and plant (Colorado State University Extension). Water regularly and begin feeding once new growth appears. In a cold-winter area, skip the garden and keep your poinsettia as an indoor plant, moving it outside only for the warm months and bringing it back in before nights drop below 55 degrees.

Do Poinsettias Like to Be Root Bound?

There is no need to repot a poinsettia you received as a gift. It will bloom perfectly well in its nursery pot right through the holidays, so leave it be during the colorful season. If the plant outgrows its container later, repot it into a slightly larger pot in late spring or early summer, after you have cut it back (Oregon State University Extension). In other words, poinsettias tolerate a snug pot and do not need frequent repotting, but they do not require being tightly root bound either.

How to Pick a Healthy Poinsettia

At the store, look for plants with plenty of healthy, fully colored bracts. Check that there is no yellow pollen showing on the little central flowers, because pollen means the plant is near the end of its bloom cycle. The best plants are full and bushy, about two and a half times as wide as the pot. If you plan to keep the decorative foil for a festive look, poke drainage holes in the bottom so the plant never sits in water.

How to Get a Poinsettia to Rebloom

Poinsettias are short-day plants, which means the colorful bracts are triggered by long nights, not by anything you feed them (University of New Hampshire Extension). Getting that holiday color a second year takes a simple seasonal routine:

• Winter (January to March): keep watering on a regular schedule while the plant is still colorful.
• Spring (March to May): once the bracts fade, let the plant rest, cut the stems back to about 6 to 8 inches, and water only when the soil is dry.
• Summer (May to September): when new growth appears, feed every two weeks with a balanced fertilizer and pinch the stems to keep the plant bushy rather than leggy. It can live outdoors as long as nights stay above the mid-50s. Repot now if it has outgrown its pot.
• Fall (starting early October): give the plant about 14 hours of complete, uninterrupted darkness every night for 8 to 10 weeks (a closet, a box, or a black bag works), with bright light during the day. Keep watering and feeding.

Once flower buds form, usually in November or December, stop covering the plant and stop fertilizing until spring. The long nights are the whole secret to turning the bracts red again in time for the holidays.

Are Poinsettias Annuals or Perennials?

Poinsettias are tender tropical perennials, not annuals. Many people treat them as a temporary holiday plant and toss them in January, but with the right care, including that long dark period each fall, the same plant can live and rebloom for years (University of Vermont Extension). In their native Mexico they are long-lived shrubs that color up season after season.

Frequently Asked Questions

Are poinsettias indoor or outdoor plants?

Both. Poinsettias are tropical plants most people grow as winter houseplants, but in frost-free Southern California (USDA zones 9 to 11) you can also grow them outdoors in the garden. Indoors they need bright, indirect light; outdoors they need full sun and protection from frost.

Can you plant poinsettias outside?

Yes, in a frost-free climate like coastal and inland Southern California. Wait until night temperatures stay above about 55 degrees, choose a full-sun spot, amend the soil with organic matter, and keep the plant out of frost pockets. In cold-winter regions, keep poinsettias as indoor plants.

Are poinsettias tropical plants?

Yes. Poinsettias (Euphorbia pulcherrima) are native to Mexico and are tropical, which is why they are frost-tender and, in the wild, grow into shrubs 10 feet tall or more.

Do poinsettias like to be root bound?

Poinsettias tolerate a snug pot and will bloom fine in their nursery container through the holidays, so there is no need to repot a gift plant in winter. They do not require being tightly root bound, though. If the plant outgrows its pot, repot it in late spring or early summer after cutting it back.

Do poinsettias need sun?

Yes. Indoors, give a poinsettia at least six hours of bright, indirect light a day near a sunny window; outdoors in Southern California, plant it in full sun. Too little light leads to leggy growth and faded bracts.

Are poinsettias poisonous?

No, not in the dangerous way the myth suggests. The milky sap can mildly irritate skin and eyes, and a pet that eats the leaves may get an upset stomach, but poinsettias are widely considered over-rated in toxicity and are not deadly to people or pets (UC Master Gardeners of San Diego County). Still, keep the sap off your skin and keep pets from nibbling.

Are poinsettias annuals or perennials?

Poinsettias are tender tropical perennials. Many people treat them as a temporary holiday plant, but with the right care, including a long dark period each fall, the same plant can rebloom for years.

How do you get a poinsettia to turn red again?

Give it about 14 hours of complete, uninterrupted darkness every night for 8 to 10 weeks starting in early October, along with bright light during the day. The long nights are what trigger the bracts to color up for the holidays.

Sources

• University of Illinois Extension, Poinsettia (botany and facts)
• University of Illinois Extension, Caring for Poinsettias
• University of Minnesota Extension, Growing and Caring for Poinsettia
• ASPCA, Poinsettia (pet toxicity)
• UC Master Gardeners of San Diego County, Poinsettia Is Not Poisonous
• University of Vermont Extension, The Perennial Poinsettia
• Colorado State University Extension, Selecting and Planting Poinsettias
• University of New Hampshire Extension, Poinsettias: Care and Reflowering

Treat your poinsettia like any other long-blooming houseplant or garden plant, and it will reward you for years. If you are looking for poinsettias for your holiday decorating, or help keeping one going afterward, visit one of our five Southern California locations and our garden experts will help you choose a plant and the supplies to care for it. For more color through the cool months, see our guide to perennials that flower during a Southern California winter.

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