How to care for a poinsettia (and keep it alive after Christmas)

A poinsettia (Euphorbia pulcherrima) needs bright, indirect light and a room between 60 and 70°F (16 and 21°C). Water it only when the top inch (2.5 cm) of soil feels dry. Keep it away from cold drafts and heat vents. Take off the foil wrap, or poke holes in it, so extra water can drain. With that care, the color often lasts well into the new year. To get the color back next fall, give it 14 hours of total darkness each night for about eight weeks, starting in early October.

Most poinsettias die from two things: a chill on the way home, and soggy roots under the foil. Fix those two and the rest is easy.

Pick a healthy plant at the store

The red, pink, or white “petals” are not petals. They are colored leaves called bracts. The true flowers are the small yellow-green buds in the center of each cluster. Pick a plant whose center buds are still tight and closed. If they are open and dusted with pollen, or have dropped off, the plant is older and will fade sooner.

Look for green leaves all the way down the stems to the soil. Skip plants with yellow lower leaves, drooping stems, or wet, heavy soil. Plants left in plastic sleeves for days tend to droop and drop leaves. Choose one that is out of its sleeve, or was sleeved that day.

Poinsettias come from Mexico. They hate cold. Air below 50°F (10°C) damages the leaves, and a few minutes in freezing wind can do it. Ask the store for a paper sleeve or a large bag, warm up the car first, and drive straight home. Do not leave the plant in a cold car while you run more errands.

Light and temperature

Set the plant where it gets at least six hours of bright, indirect light. A spot near a south, east, or west window works well. Do not let the leaves touch cold glass.

Keep the room between 60 and 70°F (16 and 21°C) during the day. Nights can drop to about 55°F (13°C), and the cooler nights help the color last. Keep the plant away from:

• Heat vents, radiators, and fireplaces.
• Doors that open to the outside in winter.
• Drafty windows.
• The top of the fridge or TV, where warm air rises.

How to water a poinsettia

Check the soil every two or three days. Push a finger into the pot. Water when the top inch (2.5 cm) feels dry.

The easiest method is to carry the plant to the sink. Water until it runs out the bottom of the pot. Let it drain for a few minutes, then put it back on its saucer. Empty the saucer if water collects there.

The foil wrap is the problem. It traps water, and the roots sit in it and rot. Take the foil off, or poke a few holes in the bottom and set the pot on a saucer.

A wilted poinsettia can mean the soil is too dry or too wet. Always feel the soil before you add water. A warm room and a small pot dry out fast, so check more often near a heat source. My post on how often to water your plants explains the finger test in more detail.

Skip the fertilizer while it is in color

A poinsettia in full color does not need food. Wait until spring, when new green growth starts. Feeding during the holidays does nothing for the bracts and can burn the roots of a plant that is not growing.

Why poinsettia leaves fall off

Leaf drop has a few common causes. Go through them in this order:

• Cold air, either a draft in the house or a chill on the way home.
• Soil that stays wet, often from foil or a full saucer.
• Soil that dried out all the way.
• Too little light.
• Sudden changes in temperature, such as a move from a warm store to a cool porch.

A few lower leaves yellowing in January is normal as the plant ages. A sudden drop of many leaves points to cold or water.

Are poinsettias poisonous?

Poinsettias are much less dangerous than their reputation. The ASPCA lists them as toxic to cats and dogs, but the effect tends to be mild, such as drooling or an upset stomach. The milky sap can irritate skin and eyes. Keep the plant out of reach of pets and small children, and wash your hands after you prune it.

Poinsettia care after Christmas

You can keep a poinsettia as a houseplant all year. Keep watering it the same way, and keep it in bright light.

In March or April, when the bracts fade, cut each stem back to about 6 inches (15 cm) tall. New shoots grow from below the cuts. Start feeding every two to four weeks with a balanced houseplant fertilizer at the strength on the label. If roots fill the pot, move the plant to a pot one size larger with fresh potting mix.

Once nights stay above 55°F (13°C), you can move the pot outside. Start it in bright shade for a week, then give it morning sun and afternoon shade. Pinch off the tip of each new shoot when it reaches 4 to 6 inches (10 to 15 cm). Pinching makes the plant bushier, with more stems to carry color. Stop pinching by mid-August, so the plant has time to set buds.

Bring it back inside before nights drop below 55°F (13°C), which in most cold areas means late August or early September.

How to make a poinsettia turn red again

Poinsettias change color when nights get long. Growers control this with blackout cloth. At home, you copy it with a closet or a box.

Start around October 1. Every night, give the plant 14 hours of complete darkness, such as 5 p.m. to 7 a.m. Put it in a closet, a spare room with the lights off, or under a large box. Even a short burst of lamp light, or a streetlight through a window, can reset the clock and delay the color. In the morning, move it back to a bright window for the day.

Keep this up for eight to ten weeks. Keep watering and feeding as usual. The bracts start to show color in November, and you can stop the dark treatment once they have colored up. Stop feeding once the color shows.

A word of honesty: a homegrown rebloom seldom looks as full as the plants in the store. Growers use controlled light, heat, and growth regulators. Reblooming is a fun winter project. If you want a showpiece for the table, buy a new plant.

Can poinsettias grow outside?

Poinsettias live outdoors all year only in frost-free places, about zones 10 to 12. In those areas they grow into large shrubs. Anywhere colder, treat them as a houseplant or a seasonal plant. Not sure of your zone? My guide on how to find your growing zone shows how to check.

More holiday plants

Poinsettias pair well with other winter bloomers. See my guides on Christmas cactus care and growing amaryllis bulbs indoors. My list of Christmas plants has more ideas, and paperwhites for Christmas covers a bulb that blooms in about a month. If you are shopping for someone, my gifts for plant lovers list may help.