A Sticky Situation

Over the past few months, Truetimber has gotten quite a few calls to look at “sap dripping from trees,” covering everything beneath them in a clear, sticky film. Most homeowners are surprised to find out that the liquid isn’t really sap, but a substance called “honeydew” (no relation to the fruit).

Honeydew is actually the excrement of plant-sucking insects such as scale, aphids, and lace bugs. More like honey-“ew”, am I right? The most commonly affected trees in our area are maple, oak, and poplar, but typically most deciduous trees and many shrubs are susceptible to it.

While honeydew can be extremely annoying and messy, it’s not inherently bad for your trees. However, an excessive buildup of the substance can lead to sooty mold, a black fungus that coats a tree’s leaves and bark and makes it hard for the tree to photosynthesize. Over time sooty mold can affect the overall health of your tree.

So what’s the solution? The first step is prevention. Leaf-sucking insects typically feed on trees that are either not healthy or stressed in some way. Making sure that your tree is healthy to begin with is a great way to ward off these insects. If your trees already have a honeydew problem, you have a few options. While Truetimber does not offer chemical applications, a common method for honeydew problems is to treat with horticultural oil or an insecticide. The final solution is to release beneficial insects into your yard that will prey on the leaf-sucking insects. The most popular choice is the ladybug. This is a great natural approach that is extremely effective. 

If you’ve got a honeydew or sooty mold problem, give us a call. We’d love to help come up with a solution for your trees!