Aspen Tree potential disease

Asked August 20, 2017, 8:41 PM EDT

I planted 7 aspen trees this spring in my backyard in Evergreen, CO. Only one of them has shown considerable growth and the others seem to be not growing. There may be one small leaf on two of them which came out this summer, but nothing on the other 3 trees. I noticed recently that 3 or 4 of them have a shinny, glistening covering on many of the leaves. The leaves look like they have moisture on them, but when i touch them they just feel kind of slippery. I noticed that a very mature aspen in our neighborhood has this same kind of leaf appearance. But other mature aspens do not have this appearance. Can you tell me what is happening to these trees?

Jefferson County Colorado trees and shrubs

1 Response

Hello,
The shiny glistening substance on the aspen leaves is most likely 'honeydew': the sticky substance excreted by aphids. Aphids are common on aspen and many other plants, and typically cause only aesthetic damage. http://csfs.colostate.edu/forest-management/common-forest-insects-diseases/common-insects-diseases-o....

Aphids would not be suspect for failure to thrive in the trees you planted this spring. This would more likely be due to water issues, planting issues or root damage. It could also be the case that the more slowly growing trees are taking longer the establish their root system than the others. Trees/plants prioritize spend energy on establishing roots over pushing canopy, so won't produce new leaves until sufficient roots have grown. A few questions to help sort this out:

  1. Were the trees from potted stock, ball and burlap, or ?
  2. If B&B, are you sure that all the wrapping material/wires were removed?
  3. Were the failing trees planted too deep? (A common occurance) First structural roots should be in the top 2-4 inches of soil.
  4. How are you watering the trees and how often?
  5. Can you send a photo of the trees?
Reference: Care of recently planted Trees: http://www.ext.colostate.edu/mg/gardennotes/635.pdf

Best regards,