Kendall County, IL Invasive Plant Rules: Prohibited Species (2026)

Kendall County does not ban invasive plants County-wide, but its subdivision regulations set a hard performance standard for every naturalized open space area approved as part of a development, including wetlands, prairies, savannas, naturalized detention basins, drainage swales, and buffers. Section 30-197(d)(2) requires that by the second growing season after planting, undesirable, invasive plant species must not be prevalent, and specifically bars seventeen named species, reed canary grass, common reed, purple loosestrife, non-native thistle, sweet clover, crown vetch, wild parsnip, burdock, garlic mustard, teasel, ragweed, Kentucky bluegrass, buckthorn, sandbar willow, honeysuckle, multiflora rose, and box elder, from being among the five most dominant species in the overall vegetative cover of any management unit.

The same subsection requires developers to submit a site-specific restoration and planting plan to the Planning, Building and Zoning Department, monitor the site for three growing seasons, and photograph permanent monitoring locations to document whether the invasive-species standard is being met. If the standard is not met by the third season, Section 30-197(d)(2)d requires the developer to prepare and submit a remedial action plan to PBZ for approval, and continued monitoring is required until the criteria are satisfied. The County points applicants to the Illinois Department of Natural Resources' website for a more complete list of invasive species beyond the seventeen named in the ordinance.