Ash Trees and Storm Prep

Is your ash worth saving?

Purdue’s EAB management guidance is the clearest rule of thumb available. Treatment can protect a healthy ash, but it isn’t recommended for trees that have lost more than 30% of their canopy. Once you start treating, keep going aggressively until the untreated ash trees nearby have died off. Once neighbors’ ash are gone, Purdue suggests watching treated trees for fresh woodpecker holes in the upper canopy or new thinning.

Why dead ash is a storm problem

Purdue’s EAB FAQ warns that dead ash becomes brittle and should be removed quickly. Brittle wood also makes removal more dangerous for the crew, since climbers may not be able to trust the limbs. Taking a dead ash down on your schedule is cheaper and safer than having a storm do it.

The same FAQ notes that EAB spreads only about half a mile a year on its own and moves much farther in firewood, so don’t move ash firewood. Suspected new infestations can be reported to the Indiana DNR at (866) NO-EXOTIC.

If the ash is in the parkway

Purdue also points out that ownership of trees between the road and your property varies, so ask your town. Hammond’s 2026 forestry plan describes a remaining backlog of dead ash. Munster removes parkway trees more than 50% dead. Hobart removes easement trees only when they’re dead or dying and funds allow. See the parkway tree guide for each town.

Storm prep checklist

• Remove dead wood. Cleaning out dead branches is the cheapest storm insurance. ISA says that kind of light pruning can be done any time of year.
• Look at the base. Mushrooms at the root flare, cracked soil or a new lean after wet weather are reasons to call an arborist.
• Never top. Purdue says topping creates weak regrowth that fails in the next storm.
• Mind the oaks. Prune oaks only December through February. Purdue’s oak wilt bulletin lists confirmed cases in Lake and Porter counties.
• Know your lines. Branches near the service line to your house are for NIPSCO to clear, not you.
• Know your policy. Typical policies cover damage to structures from covered storms, not removal of a tree that fell on nothing (Iowa Insurance Division, general guidance).

When the storm hits anyway

After the August 11, 2026 storm, Purdue’s forestry extension published Trees and Storms: Understanding the Damage. It walks through wind throw, stem failure, crown twist, root failure (consider removal past about 30% of roots exposed) and branch failure. It also warns that less credible companies follow storms, and recommends an ISA Certified Arborist. Our storm damage page covers the first hours, and the tree removal page covers hiring.