Sticky Aspen: The sticky and shiny residue is honeydew, which is probably created by aphids. You can check for these little insects by looking on the under-side of the leaves of your Aspens (or other trees and shrubs). One easy way to treat this problem is to spray the tree with a strong upward spray of water with a nozzle on your garden hose. Aphids will often be washed off or killed by the water spray.

Aspens are often sensitive to chemicals (leaves will turn black) and water is a safe treatment. However, products such as cygon, orthene, or isotox can also be used, or even easier is a soil treatment with ferti-lome's Systemic Insect Drench. We have a favorite organic spray called Spinosad Soap that is easy to spray on.