St. Louis, MO Landscaping Rules: Weed Ordinances (2026)

Two sections of the St. Louis Revised Code speak to weed height, and each prints its own figure and its own enforcement path.

Chapter 11.04, the weeds chapter, is built around § 11.04.040. It names Russian, Canadian, or common thistle, wild lettuce, wild mustard, wild parsley, ragweed, milkweed, ironweed, and poisonous plants or shrubs, and it reaches all other unattended vegetation and noxious weeds that have attained a height of seven (7) inches or more on any lot or lands within the City. It also covers unattended growths of shrubs, trees, and seedlings that, in the opinion of the Commissioner of Forestry, are unsightly and can impede the clearing of a lot. Every owner, occupant, or person in control of the land must keep it free of these weeds by destroying them, by cutting or spraying with a chemical compound approved by the United States Department of Agriculture and the United States Environmental Protection Agency, by digging under, or by any other method the Commissioner of Forestry approves.

Section 25.32.020 amends the 2018 International Property Maintenance Code that § 25.32.010 adopts as the Property Maintenance Code of the City of Saint Louis. Its section 302.4 requires all premises and exterior property to be maintained free from weeds or plant growth in excess of eight inches, and it prohibits all noxious weeds. Weeds under that section are all grasses, annual plants, and vegetation, with the "other than" language in the definition setting apart trees, shrubs, cultivated flowers, and gardens.

The enforcers differ. Chapter 11.04 defines the Forestry Commissioner as the Forestry Commissioner of the City of St. Louis or a designated employee, including a neighborhood stabilization officer or neighborhood improvement specialist. Section 11.04.130 makes enforcement the joint responsibility of the Forestry Commissioner, Health Commissioner, and Police Department. The Property Maintenance Code works through the building official, defined as the Building Commissioner of the City of Saint Louis or any duly authorized representative, who is authorized to serve the notice of violation. Section 302.4 then authorizes a duly authorized employee of the Forestry Division, or a contractor hired by the City, to enter the property and cut and destroy the weeds once the owner fails to comply with that notice.