Ash trees and emerald ash borer

The emerald ash borer was first found in Kentucky in 2009, and Jefferson County was among the early finds. source Since then, many untreated ash trees in Louisville have died or are dying.

How to tell an ash

Ash trees have leaves made of five to eleven leaflets in pairs, and branches that grow in opposite pairs. Mature bark has a diamond pattern of ridges. If you are not sure, a tree service can tell you on site.

Signs of trouble

• Thinning leaves at the top of the crown
• Woodpeckers stripping off patches of bark
• Small D-shaped exit holes, about an eighth of an inch across
• Long vertical splits in the bark
• New shoots sprouting low on the trunk

Treat or remove

A healthy ash with most of its crown can sometimes be saved with regular treatments, usually given every year or two. Once a tree has lost much of its crown, treatment is less likely to work. Ask the tree service for an honest view of the tree before paying for treatment.

Why waiting costs more

Dead ash dries out and turns brittle fast. Limbs snap without warning, and climbers may not be able to safely tie into the tree. That can mean a bucket truck or crane where a climber might once have done the job. A dead ash near a house or street is worth dealing with soon.

What to replant

Replacing an ash with a different species means one pest cannot take out every tree again. Ask the tree service or a nursery what grows well in Louisville soil.

Questions for the crew

• Is this tree an ash, and how far gone is it?
• Can it be climbed safely, or does it need a lift?
• Does the price include the stump and cleanup?
• Are any other ash on the lot worth a look?

Tree on a power line? Stay back at least 30 feet and call 911 or your utility.

Firewood rules

Moving ash firewood can spread the borer to new places. Burn it close to where it was cut, or ask the crew to chip or haul it away. Chips make good mulch for beds once they age a few months.