Poinsettia Care Tips: Tony Fulmer, Chalet’s Chief Horticulturist, says, “the key to success with Poinsettias is bright light.” Allow the soil surface to dry thoroughly to the touch before watering, always using warm water. Don’t splash water on the bracts (the colored leaves we refer to as flowers, which really aren’t). Don’t let poinsettias sit in drainage water for more than 30 minutes after you’ve watered them. Avoid temperature extremes, hot or cold, inside or out. Never let them sit in a cold car while you shop and the car interior grows cold. Conversely, don’t put them near an actively used fireplace, heat vents, or radiators.