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

Section 317-46, Design standards, sits in Chapter 317's Article VII Stream Buffer Regulations, which govern vegetated buffers the county requires along protected streams, wetlands and floodplains in the unincorporated area. Subsection (2) lists invasive species by common and botanical name: common, glossy, saw-toothed, Dahurian, Japanese and Chinese buckthorn, Tartarian and Japanese honeysuckle, autumn olive, kudzu, round-leaved bittersweet, multiflora rose and purple loosestrife, alongside Tree of Heaven. The code frames these as plants that will damage native ecosystems if planted in a required buffer, and notes most already sit on the Illinois Banned Species List, making them illegal to buy, sell or plant anywhere in the state, not just in McLean County.

Section 317-47 then requires buffers to be vegetated in their natural state or with appropriate nursery stock as listed under § 317-46E, and directs that where necessary, removal of these invasive species is allowed before native vegetation is reestablished. The buffer article applies to protected property in the unincorporated county identified on the county's stream buffer map or by field observation from the Director of Building and Zoning.