If you're noticing that the leaves of your poinsettia are falling off, there are a few things that could be causing it. Here are some possible reasons:
1. The plant is too dry - Poinsettias need to be kept moist, but not soggy. If the leaves start to droop and then fall off, it's likely that the plant is too dry. Try increasing the frequency of your watering schedule and make sure that you're giving the plant enough water each time.
2. The plant is too cold - Poinsettias are tropical plants and prefer warm temperatures. If they get too cold, their leaves will start to turn yellow and fall off. Make sure that your poinsettia is not near any drafts or windows where it might be getting chilly.
3. The plant is getting too much sun - While poinsettias do need some sunlight, too much sun can cause their leaves to fade and eventually drop off. Move your plant to a spot where it will get indirect sunlight throughout the day instead of direct sunlight for long periods of time.
4. Nutritional problems - Lack of nutrients can also cause poinsettia leaves to fall off. Make sure you're fertilizing your plant regularly (about once a month) with a balanced fertilizer made specifically for flowering plants like poinsettias