Coming up in late winter/early spring, many of our Castle Rock clients get a dormant oil treatment on their aspen or pine trees.
Given these are two key species in your environs, dormant oil treatments prevent needle scale on pine trees and oyster shell scale on aspens.
Needle scale on pine treesThe scale is more easily controlled in early spring than any other time of the year. Typically a dormant oil treatment is done in mild, late winter weather (40 to 60 degrees) because discoloration and staining can occur on nearby trees when temperatures are higher.
“Pine needle scale is an elongate, white insect that attaches itself to the needles of several pines, notably mucho,” according to CSU.
Premature or abnormally large needle drops on your pines, especially pines may indicate its presence.
Our staff sees this most commonly on aspen and has observed the tell-tale oyster shell pattern on stems and branches of ash trees. Oystershell scale is regarded as a tree killer due to the aspen’s susceptibility to disease once the scale has sapped its vigor.