I have had a poinsettia for about a week. It is not receiving indirect sunlight, the room is not cold (average temperture 18 to 20 C), and it has not been over watered. Yet, all the green leaves are dropping off.
Certified GKH Gardening Expert
Check the room for drafts. Poinsettias are very subceptible to cold air. Even if the overall room is the right temp, if a cold draft is hitting it, say when a door opens or from a drafty window, this can cause leaf drop.
Poinsettia stay freshest in a cool room. It it get too hot the leaves will drop. Keep them in a room that is 60-65 degrees at night.-70-75 during day. Ideal location is south or west window with bright light, doesn't have to be direct. Keep away from drafts, window, doors or heating vents.