By Mary Small, Colorado State University Cooperative Extension, Urban Integrated Pest Management
Leaves on houseplants can drop for many reasons. When a new plant is brought home, it may shed leaves in response to lower light intensities there. Usually, once the adjustment is make, leaf drop ceases, unless the plant won't tolerate reduced light conditions.
Temperature changes also can cause leaf drop. Low humidity in Colorado during winter can be another cause. Usually placing plants in naturally humid areas, such as the kitchen or bathroom, will help as long as other growing requirements are met.
The prime suspect in leaf drop, though is overwatering. The top of the soil in a potted plant dries out fast, especially in winter, but underneath it can still be moist. Before watering, it's a good idea to check the soil by pushing a finger into the soil to your first or second knuckle. If the soil is moist to the touch, wait a day or two, then recheck. When the soil feels dry at the depth you are checking, it is time to water. Put enough water on the soil so the excess comes out of the bottom of the container. Let it drain for 15 or 20 minutes, then discard the excess water.
Photograph courtesy of Judy Sedbrook.
© CSU/Denver County Extension Master Gardener 2010
888 E. Iliff Avenue, Denver, CO 80210
Date last revised: 01/05/2010