By Mary Small, urban integrated pest management agent for Colorado State University Cooperative Extension
Problem: Potted, scented geraniums brought in for the winter have tiny green aphids clustered on the plant's tips, and the leaves are sticky.
Solution: Aphids such the sap out of plants and excrete a sugary substance called honeydew that makes the leaves sticky. Aphids are especially attracted to succulent parts of the plant because their mouthparts can easily pierce them.
Avoid excess fertilization, which stimulates the formation of tender, succulent growth. You can also place the plant in the kitchen sink or a bathtub and hose off the insects. You may need to repeat the procedure a few times, but it should take care of the problem if you're persistent.
Another option is to prune off the most heavily infested plant parts unless such pruning would really deform the plant. You also could apply insecticidal soap, using a formulation labeled for houseplants. Monitor the plants closely and reapply the product if needed according to label directions.
Photo: Judy Sedbrook
© CSU/Denver County Extension Master Gardener 2010
888 E. Iliff Avenue, Denver, CO 80210
Date last revised: 01/05/2010