Why Is My Poinsettia Losing Its Leaves?

Have your poinsettia been exposed to cold temperatures?

Is the room where you're keeping your plant too hot?

Have your poinsettia been wrapped for a longer period after purchasing?

Is the air in your home too dry?

Have you been watering your poinsettia too rarely?

Have you been overwatering your poinsettia?

Is your poinsettia placed in a shady spot?

Are there any insect pests present on your poinsettia?

Poinsettias are very sensitive to cold temperatures. If it's exposed to the temperatures of 50 °F or lower, even for short periods, the poinsettia can get stressed and drop its leaves. You should keep your poinsettia indoors where it's warm at all times. The ideal temperature for a poinsettia is between 60 and 75 °F.

Just like the cold temperatures, high temperatures can also stress out poinsettias to the point where it will drop its leaves. The ideal temperature for a poinsettia is between 60 and 75 °F.

Like many plants, poinsettias give off a gas called ethylene. Ethylene is a hormone that affects the ripening and flowering of many plants. If your plant is kept inside a closed plant sleeve for a few days, the concentration of ethylene will increase and leaves will begin to fall.

Poinsettias can tolerate dry air fairly well, but often if the humidity is constantly below 30% the plant will get stressed and the leaves will drop off. A good indicator of dry air is if the soil dries out very quickly after a good watering (in 2-3 days). Increase the humidity using a humidifier or place the plant on a humidifying tray.

One of the causes of stress in poinsettias is insufficient water. A poinsettia will need enough water to keep the potting soil moist at all times but never soggy. You should water your poinsettias whenever the soil feels dry to the touch, about once per week.

Overwatering can be another reason for poinsettias to stress and drop their leaves. A poinsettia will need enough water to keep the potting soil moist at all times but never soggy. You should water your poinsettias only when the soil feels dry to the touch, about once per week.

Because poinsettias are from Central America, they are used to a fair amount of sun. It will react negatively to the lack of sunlight and sometimes it will drop leaves. Place your plant by a well-lit window, so that it can receive the proper amount of sunlight. East-facing windows are best so that they can catch the morning’s glow and bask in the afternoon’s shade.

Whiteflies love poinsettias, piercing the leaves to suck up their sap, thus causing their foliage to slowly turn yellow and then drop off. Spider mites, mealybugs, and scale are other sap-sucking insects that also sometimes infest poinsettias and give similar results. Different treatments, including sprays with insecticidal soap, neem oil, horticultural oil, rubbing alcohol, etc., can be used to control the pests.

It is perfectly normal for a poinsettia to lose a leaf or two from time to time. That’s its way of getting rid of older, less functional leaves. Pick up and remove dropped leaves. New leaves will replace the old ones in due time.