Is emerald ash borer still a problem in Joliet?

Yes. The City lists confirmed EAB locations as citywide, and Extension says fewer than 1% of untreated ash typically survive where EAB is established.

Is it too late to treat my ash tree?

Not always. U of I Extension says recovery is likely if the tree still has 70% or more of its canopy. Treatments last one to three years and must be repeated.

Can I plant a new ash on the Joliet parkway?

No. The City removed all ash species from its approved planting list in 2005.

Emerald Ash Borer in Joliet, IL: Timeline & What to Do Now

The short version

The City of Joliet's Forestry page lists confirmed EAB locations in one word: citywide (Joliet Forestry). University of Illinois Extension says that where EAB has been around a while, fewer than 1% of untreated ash trees typically survive (U of I Extension). So if you have an untreated ash in Joliet that still looks fine, don't count on it staying that way.

How it got here: the timeline

2002. EAB is discovered in southeastern Michigan, near Detroit, as the cause of dying ash trees. It likely arrived from Asia in wood packing material (Illinois Dept. of Agriculture).
2004. Joliet starts planning for the borer, years before it shows up here (Joliet Forestry).
2005. The City estimates ash make up about 20% of all street trees. Forestry pulls every ash species off the approved planting list, so nobody, City, homeowner or developer, can plant ash in the public right-of-way (same page).
June 9, 2006. The first Illinois find: two infested ash trees in "The Windings" subdivision near Lily Lake in Kane County (IDOA).
May 16, 2011. Joliet adopts its EAB Management Plan (Joliet Forestry).
July 2012. City arborist Jim Teiber tells Patch that as many as 80% of the city's ash may be infested. Up to 200 trees are coming down that year, with $100,000 to $150,000 budgeted for removals, and he expects 2013 to be the year dead and dying trees show up on a mass scale (Patch).
December 2013. The City announces it will remove every parkway ash in two subdivisions: Warwick, off Essington Road and Theodore Street, and Grand Prairie, off Hennepin Drive south of the Louis Joliet Mall. It expects to remove more than 1,000 trees that year and likely that many again in 2014 (Patch).
Jan. 14, 2021. USDA APHIS ends the federal domestic EAB quarantine (USDA APHIS).
Fall 2021. The City reports it has planted 1,000 trees a year for the past six years under a 10-year contract to replace trees lost to EAB, with about 500 more that fall to finish year seven. Parkway trees go in at no cost to the resident, and the City arborist picks the species to keep the urban forest diverse (WJOL).
Today. Confirmed locations: citywide. The City also warns that a marked parkway tree may not be removed for five to seven years because of the sheer number of infected trees (Joliet Forestry).

Your own ash: what to do now

Step 1: look at it honestly. The City's list of signs: thinning and dying branches in the upper third of the crown, suckers sprouting from the base and trunk, vertical bark splits, woodpecker damage, tiny D-shaped exit holes about 1/8 inch across, and S-shaped tunnels under the bark. The City says an infested tree typically dies in about three years (Joliet Forestry). Extension adds that big ash can take six to seven years (Extension).

Step 2: decide treat or remove. Extension says recovery is likely if a tree still has 70% or more of its canopy when it's treated, and that treatments last one to three years, so they have to be repeated (Extension). The Illinois Department of Agriculture says to focus treatment on ash that show no signs of infestation, are in good overall condition and are worth keeping, to check local ordinances with your public works department first, and to have a certified arborist judge whether the tree is a good candidate (IDOA).

Step 3: if you treat in Joliet, know the City's rules. Joliet says the two products it lists, a soil drench and a trunk injection, must be applied by a certified arborist licensed with the City of Joliet to do tree work, and that the resident pays, possibly for a number of years (Joliet Forestry).

Step 4: if it's past saving, take it down before it gets brittle and starts dropping limbs. That's a tree removal job, and the long-dead ones are covered on our dead ash page.

Step 5: deal with the wood. The Morton Arboretum says removing and destroying infested trees that won't benefit from treatment helps slow the spread, and to avoid moving firewood (Morton Arboretum). The federal quarantine is gone, but APHIS says state rules may still apply (APHIS). Burn it where it was cut, or have the crew chip it.

Parkway ash are the City's

An ash between the sidewalk and the curb is City property. The City isn't treating parkway ash. You can treat one yourself, but you have to give the City proof of the work and who's doing it, and the City Arborist has to be consulted first (Joliet Forestry). A painted number on the trunk means it's on the removal list. Dead parkway tree? Call 815-724-3650. The whole set of rules is in our Joliet parkway tree rules guide.

After the stump

Ash is still off the City's approved list, so whatever goes back in the parkway will be something else (Joliet Forestry). On your own lot, grind the stump below grade before you replant, and call 811 first.

Bottom line: healthy and valuable, get it looked at for treatment. Thin, sprouting or woodpecker-stripped, plan the removal now, not after the next storm.

Sources

Checked Nov. 4, 2026. If a City rule has changed since, the City’s page wins.

Emerald ash borer in Joliet: the timeline, and what to do now