3 Steps to Save Ash Trees From the Emerald Ash Borer

Denver is a city teeming with ash trees. One in every six urban trees in the Denver area is an ash, so the trees help fill out the canopy in parks, greenbelts, and landscaping. If the destructive emerald ash borer (EAB) continues to invade Colorado, ash trees will die in mass numbers. Here are three ways you can help defeat the deadly EAB.

1. Identify Ash Trees on Your Property

If you live in or around the Denver region, inventory your trees to determine which ones are ash trees. Your tree service professional can help you identify all of your trees if you aren’t sure.

Tie a stringed tag or colored ribbon around one limb or branch of each ash tree you locate to help you monitor trees even when leaves are missing in fall and winter. After identifying and tagging your trees, decide which trees are worth saving should the EAB infest your ash trees.

Experts recommend that smaller affected trees be removed and destroyed by professional tree-removal companies. Mature, stately ash trees may be salvageable if EAB infestations are caught in time.

2. Recognize the Signs of EAB Infestation

The ½-inch long EAB insect has interesting colors that catch the eye. The wings and head are a metallic green. When the wings separate, you see the purplish-bronze abdomen.

However, by the time you spot any significant numbers of EAB individuals, the infestation is likely to be several years old. That’s because the larvae of the EAB can remain under the bark of trees for several years before the adults emerge.

Other signs of EAB infestation include:

    • Thinning canopy
    • Sparse foliage on random limbs
    • Green shoots growing from trunk base
    • D-shaped adult exit holes
    • Serpentine-shaped tunnels under bark
    • If bark splits along the trunk of an ash tree, this is a sign of EAB damage. As the larvae tunnel through the vascular layers of the tree, the wood becomes less flexible. The bark cracks with movement due to the newly brittle wood.

Another sign of EAB infestation is the presence of the Northern Flicker woodpecker. This brown bird pecks away at the ash tree’s bark to reach the juicy larvae inside.

3. Contact Your Tree Service Company

When you have any type of ash trees on your property, contact your tree service to help you manage their care. Even if you don’t find evidence of EAB in your own landscape, your neighbor’s or the nearest town’s ash trees could be infested. Experts advise property owners to schedule preventative EAB treatment if an infestation is within 10 to 15 miles of your trees. Your local forestry office or your tree service can help you determine whether your trees are within the range. Your tree service can apply preventative treatments to your trees that are not infected. If trees have only a few galleries of EAB, a systemic insecticide will most likely save the tree. However, treatment can’t undo any damage done to the tree.

If a tree has a large number of larval galleries under the bark, the phloem and xylem of the tree have been severely compromised. A systemic insecticide won’t be able to travel through the vascular system of the tree due to the damage done to fluid- and nutrient-transporting layers.

A tree service professional can also use foliage sprays to target the adult EAB. Mature females consume ash foliage for at least two weeks before they lay eggs, so non-systemic foliage sprays can help cut down on new infestations.

According to Insecticide Options for Protecting Ash Trees from Emerald Ash Borer, if more than 50 percent of an ash tree’s canopy has died back due to EAB, the tree is best destroyed. Trees with substantial damage may look worse after treatment for EAB but can come back from infestations within a few years to grow new canopy foliage.

Schedule an inspection and treatment of your ash trees by contacting the professionals at Ross Tree Company today. We offer expert tree injections to help prevent and treat EAB infestations in the Greater Denver, Colorado region.