Atchison County warns landowners of Kansas noxious weed list changes

Atchison County landowners now have a revised Kansas noxious weed list to follow, and the changes affect the places most property owners overlook first: pasture edges, fence lines, drainage ditches, rights-of-way and roadside vegetation.

The county warned Wednesday that the updated list takes effect May 15, 2026. Added to Category A are diffuse knapweed and spotted knapweed. Common teasel and cutleaf teasel moved into Category B, and Amur honeysuckle was added to Category C. Native pignut was removed from the Kansas noxious weed list.

That matters because Kansas divides noxious weeds by spread and urgency. Category A weeds are generally not found in the state or have only limited distribution, Category B weeds have discrete distributions, and Category C weeds are already well established in larger populations. Under state law, landowners must control designated noxious weeds using approved management methods that prevent viable seed production and, where relevant, destroy the plant’s ability to reproduce vegetatively.

The Kansas Department of Agriculture says noxious weeds threaten native plant species, crops, wildlife habitat, erosion control and property values. Its 2026 changes were based on weed risk assessments from the Kansas Noxious Weed Advisory Committee, followed by a public hearing April 7 in Manhattan. The additions and approved control methods were published in the Kansas Register on April 30.

For Atchison County residents, the practical response is immediate: inspect fields, ditches, disturbed ground and road margins now, especially on land that is rented out, inherited, or managed from a distance. Pasture owners, township supervisors and anyone responsible for roadside vegetation should look for the new Category A and B weeds before they flower and set seed. The county’s noxious weed department helps landowners control weeds on state, county and township lands, and it is the office to contact for inspection or compliance help.

Atchison County also points to a chemical cost-share program that offers herbicides at 75 percent of retail cost, giving landowners a lower-cost way to get ahead of the new requirements. With the state list changing and local enforcement tied to it, the safest approach for property owners is to check now and treat quickly, before the new weeds spread into more ground across the county.