Gaithersburg, MD Landscaping Rules: Weed Ordinances (2026)

Montgomery County Code Chapter 26 (Section 26-9) establishes the 12-inch maximum height standard for weeds, grass, and rank vegetation on all properties within Gaithersburg, applying equally to front, side, and rear yards on residential, commercial, industrial, and vacant lots. The definition of weeds under the code is broad and includes any uncultivated vegetation that has grown beyond the 12-inch threshold, regardless of species. This standard applies to the entire lot including fence lines, alleys, tree wells, and unmaintained areas behind structures. Complaints about overgrown properties are investigated by Gaithersburg Neighborhood Services (for owner-occupied and commercial properties) at 301-258-6340 or Neighborhoods@gaithersburgmd.gov, or by DHCA (for rental properties licensed under the county rental program). When a violation is confirmed through inspection, the property owner receives a written notice specifying the violation location, required corrective action, and compliance deadline (typically 7 to 14 days). If the owner does not abate the weeds within the deadline, the city or county arranges for a contractor to clear the vegetation and bills the full cost to the property owner, including administrative fees. Unpaid abatement costs become a lien against the property. The Montgomery County Pesticide Law (Bill 52-14) adds a unique dimension to weed management in Gaithersburg that does not exist in most other jurisdictions. Effective January 1, 2018, the law prohibits the use of cosmetic pesticides -- defined as pesticides applied for purely aesthetic purposes rather than to address a threat to human health or to control invasive species -- on lawns, landscapes, playgrounds, mulched areas, and property associated with childcare facilities. This prohibition covers most conventional synthetic herbicides used for lawn weed control, including products containing glyphosate, 2,4-D, dicamba, and other active ingredients commonly found in consumer weed-killer products. Homeowners and lawn care companies must instead use organic products or EPA 25(b) minimum-risk pesticides for routine lawn weed management. The law includes exceptions for agriculture, golf courses, gardens (food production), invasive species control, and applications necessary to protect human health (such as controlling poison ivy near walkways or treating for disease-carrying pests). Professional lawn care companies operating in Gaithersburg must comply with the Pesticide Law and are subject to inspection by the county Department of Environmental Protection. The practical effect is that Gaithersburg residents need to rely more heavily on cultural practices -- proper mowing height, overseeding, soil amendment, and manual removal -- to manage weeds rather than chemical herbicides.