Poinsettia care: bracts, watering and reblooming

Light

Indoors, put the plant where it gets at least six hours of bright, indirect light, the figure both Clemson and Illinois Extension give. A spot a few feet back from an east or west window works well, as does a south window with a sheer curtain. Clemson warns that direct sun through glass can fade the bracts, so filter it while the plant is in color. Keep the leaves from touching the pane, since cold glass damages them.

The rules change once the holidays are over. A poinsettia you keep growing wants as much sun as you can give it: Illinois suggests a sunny window after the spring cutback, then a summer outdoors with six to eight hours of direct sun and some afternoon shade once nights stay above 50°F. Move it out gradually over a week or two so the leaves do not scorch.

Water

Poinsettias like moderately moist mix, never soggy and never dry. Push a finger into the surface: when it feels dry, carry the pot to the sink, take it out of any decorative cover, and water until it runs from the drainage hole. Let it drain fully before it goes back. Clemson says never to let the mix dry out completely, and Illinois adds that a wilted plant drops its bracts sooner, so a missed watering shows up as bare stems a week later.

The foil wrapper sold on most holiday plants is the hidden problem. It holds water around the roots like a bucket, and the plant rots while the surface looks fine. Illinois advises punching holes in the foil so water can drain into a saucer, then tipping out the excess. Removing it altogether is simpler.

If you plan to keep the plant, its water needs drop sharply in late winter. Once roughly half the leaves and bracts have fallen, Illinois recommends tapering off until the mix is completely dry so the plant goes dormant, then storing it somewhere cool and dark with just enough water to keep the stems from shriveling. Regular watering resumes when new growth starts, usually in early May.

Soil and pH

A good bagged potting mix is fine for the holiday season. When you repot in early summer, choose one rich in organic matter: Clemson suggests a mix with a considerable amount of compost, leaf mold or peat moss, and NC State describes a well-drained blend of loam, organic matter and peat. Drainage holes are essential, since this plant goes from thirsty to rotting quickly in a heavy, airless mix.

Humidity

Average household humidity is acceptable, though a heated house in December is drier than a poinsettia likes. UF/IFAS notes that slightly humid air helps prolong bract color and life span, and suggests a gravel tray under the pot. Grouping the plant with other houseplants raises humidity around it a little, as Illinois points out. Keep it away from forced-air vents, which dry the leaves and the mix at the same time.

Temperature

Temperature decides how long the color lasts. Illinois Extension gives a range of 55 to 70°F (13 to 21°C), with about 65°F (18°C) as the sweet spot, and suggests days of 60 to 70°F with nights near 55°F. Clemson draws the hard lines: above 70°F by day the leaves yellow and the bracts fade early, and below 50°F (10°C) chilling injury causes leaf drop. Even a few minutes of cold air in a parking lot can damage the bracts, so have the plant sleeved when it is below 50°F outside.

Fertilizer

Do not feed a poinsettia while it is in color; Clemson, Illinois and UF/IFAS all agree on that point. Fertilizer becomes useful only once you decide to keep the plant growing. Illinois suggests a houseplant fertilizer once a month after the holidays and every couple of weeks during the summer outdoors. Clemson recommends a balanced complete fertilizer such as 10-10-10 every two to three weeks through spring, summer and fall. Stop when the dark treatment starts in autumn.

Work out the dose for your watering can with the fertilizer dilution calculator →

Repotting

A holiday plant does not need a new pot. Repot only if you are keeping it, and do it after the spring cutback, when shoots are pushing. Illinois times this for early May, when you cut the stems back to 4 to 6 inches; Clemson suggests early June and a container 2 to 4 inches larger than the old one. That is a bigger jump than most houseplants get, because a poinsettia grown outdoors for the summer fills a pot quickly. Pinch the shoot tips through summer for a bushy plant, but stop by September 1, the cutoff Clemson gives.

• New shoots appear after the spring cutback and roots fill the pot
• The plant wilts between normal waterings in summer
• Roots grow through the drainage holes

Propagation

New plants come from stem cuttings. NC State recommends taking them in early summer, dipping the ends in rooting hormone and sticking them in a mix containing peat moss, perlite and vermiculite. The tips you pinch off in June are ideal material. Expect the milky sap to bleed from every cut; wear gloves and keep it away from your eyes.

Methods: Stem cuttings dipped in rooting hormone, in a peat, perlite and vermiculite mix · Best season: early summer.

Common problems

Leaf drop is the complaint behind most poinsettia questions, and it has several causes: cold below 50°F, poor light, wilting from dry mix, or crowding at the store. Yellow lower leaves usually mean heat or a rotting root system. Whiteflies are the most common pest, with mealybugs, soft scale and spider mites behind them, so check leaf undersides before you buy. Bracts that stay green the next year almost always point to nights that were too warm or interrupted by light.

Not sure which one it is? Try the plant problem diagnosis tool →

Is the poinsettia toxic to cats and dogs?

The ASPCA lists the poinsettia as toxic to cats, dogs and horses, but its own entry adds that the plant is generally over-rated in toxicity. The irritant sap can upset the mouth and stomach and sometimes causes vomiting. Extension services say much the same: NC State rates it of low severity and notes that a significant amount must be eaten before a mild stomachache, Clemson says it is not considered toxic, and UF/IFAS calls the poisonous reputation a popular belief. The real risk is the latex sap, which can irritate skin and eyes and affect people with latex allergies. Keep it out of reach of a pet that chews leaves, and call your veterinarian if one eats a lot.

Check any other plant against the ASPCA lists →