Invasive Plant Rules in Cook County, IL (2026)
2 county-level rules, plus city-specific rules for 4 cities in Cook County, Illinois.
Verified from official government sources
Prohibited Species
Required landscape plans in unincorporated Cook County may not use invasive species like buckthorn, purple loosestrife, and garlic mustard.
Cook County Bans Invasive Plants in Landscaping
Some RestrictionsCook County Code § 126-64(d)
Invasive plants may not be utilized. A list of invasive plants that may not be utilized, and alternatives that may be utilized, is set forth in the table below... Rhamnus cathartica Common buckthorn R ... Lythrum salicaria Purple loosestrife R ...
Tree-of-Heaven Removal
In unincorporated Cook County, landscape plans required for building permits, PUDs, and parking lots over 20 spaces may not use tree-of-heaven (Ailanthus altissima): it's flagged for removal on the county's own invasive-species list.
Cook County Bars Tree-of-Heaven In Landscaping
Some RestrictionsCook County Code § 126-64
Invasive plants may not be utilized. A list of invasive plants that may not be utilized, and alternatives that may be utilized, is set forth in the table below: ... Ailanthus altissima | Tree-of-heaven | R | Fraxinus spp. (ash species) ... R = Remove as soon as possible, including all cultivars, and/or do not add to collection in future
Invasive Plant Rules by City in Cook County
4 cities in Cook County have their own invasive plant rules rules. Each link goes to that city's dedicated page with code citations.
All Cook County ordinances
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