Why Is My Poinsettia Dropping Leaves?

Leaf drop is a stress signal

Iowa State University Extension says leaf drop is most likely some kind of environmental stress, and that improper watering is the most common one. New Mexico State University Extension explains why the plant reacts this way: the poinsettia is adapted to dry conditions and drops leaves to cut its water loss. Find the stress and the dropping stops, though the leaves already lost do not come back on those stems.

Read the symptom

New Mexico State adds a timing note: leaves can fall several days to a week after the stress that caused them, so the cause may be a cold car ride or a dry spell before you bought the plant.

More on poinsettias

• Poinsettia care — light, water, feeding, leaf color, repotting, and when a pot goes outside in your zone
• How to Water a Poinsettia, and How Often
• Why Is My Poinsettia Dropping Leaves? — this page
• Poinsettia Care After Christmas: Keep It and Rebloom It
• Poinsettia Tree Care: Keeping a Tree-Form Poinsettia
• Growing Poinsettias Outdoors by Zone (Zones 9–11)
• ZIP code zone finder — your exact USDA zone, to read the tables on these pages against

Watering

Iowa State’s fix: check the soil every day, water when the surface is dry until water runs from the bottom of the pot, do it in the sink with the pot out of its decorative cover, and never let water sit in the cover or saucer. University of Delaware Cooperative Extension says a plant left to wilt drops its leaves early. The watering guide has the full method.

Cold, drafts and heat

Iowa State says even a brief moment in freezing air can blacken leaves, that the damage cannot be undone, and that the defense is wrapping the plant for the trip home and making it your last stop. Indoors, keep it from touching a cold window pane and away from outside doors and heat registers; Iowa State names warm, dry air from a furnace register and rapid temperature swings near a door as causes of leaf drop. NC State Extension in Clay County names sudden temperature changes and hot or cold drafts too.

New Mexico State says the worst place is warm, dry and dim, and the best is cool, humid and bright. Its advice for a plant you want to show off in a warm room is to move it there for the occasion and back again afterwards.

Root rot

Iowa State says sudden wilting and collapse is most likely root rot, which develops when plants are watered too often and the soil stays saturated. NC State Extension’s plant toolbox also says overwatering causes root and stem rot. Let the surface dry before watering and empty any water that drains into the cover or saucer. New Mexico State says root rot is more likely to kill the plant than drying out is.

Whiteflies

Iowa State describes whiteflies as small, white, moth-like insects that flutter up when the plant is moved and feed on the sap, and says heavy infestations yellow the leaves and make them drop. It says they are very hard to control indoors, that insecticides are not a good option because they are not very effective, and that prevention at the store is the best defense: check a plant before you buy it. A light infestation, Iowa State says, is often best tolerated until the plant is discarded after the holidays.

Is it worth saving?

New Mexico State says that if only a few leaves fall you need do nothing. If many fall, the plant may still live if the stems look healthy, but it will not color again in time for this Christmas; it begins to grow again after several weeks to a couple of months. To bring a bare plant back, New Mexico State corrects the cause first, then prunes the stems to leave 3 to 6 inches and gives it bright light and a little more water as new shoots appear. The after-Christmas guide picks up from there.

We found no Clemson, LSU AgCenter or Texas A&M source on poinsettia leaf drop that we could read.