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Tree Preservation

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The City of Longmont Forestry Services has surveyed all public ash trees and selected approximately 900 of the total 2,700 ash trees that meet the criteria for treatment which includes:

  • Diameter of tree is greater than 10 inches. Removing and replacing smaller trees reduces the overall use of pesticides in Longmont.
  • The tree has little to no crown, stem or root damage and has a form that will create a structurally sound tree at maturity.
  • Trees growing near surface water will not be treated and will be preemptively removed or left to die naturally. Tree-Age, the pesticide we used for ash tree treatments has long persistence in ash trees and is highly toxic to aquatic invertebrates. Currently, there is no research on the pesticide residues in fallen leaves.

Ash trees that are selected for treatment are painted with an emerald green dot at the base of the tree and will be treated on a three-year rotation. Prior to each treatment cycle the ash trees are evaluated for the above criteria.

Experiences from the Midwest has shown that without treatments communities are faced with quick and catastrophic tree losses that municipal budgets cannot afford. Pesticide treatments for EAB will help Longmont preserve our urban forest canopy, and extend the EAB management timeline by moderating budgets from year-to-year.


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