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Montgomery County's lawn pesticide law

In most of Montgomery County, only organic or minimum-risk pesticides can be used on lawns, playgrounds and childcare grounds. There are exemptions for things like invasive weeds and insects that bite or sting.

Last reviewed 29 September 2026 · Every rule links to its official source

Where the law applies

The law restricts which pesticides can be used on private lawns, playgrounds, mulched play areas and childcare facilities in Montgomery County.1 It was passed in 2015 and upheld by the Maryland Court of Special Appeals in May 2019.2

It covers the whole county except Laytonsville, which hasn’t opted in.3

What you can use

Only organic or minimum-risk pesticides are allowed on those areas.1 The county publishes a list of allowed products.

The rule is about lawns. You can still treat a pest that’s attacking a tree or shrub, even if you apply it on the lawn.4

Exemptions

On private property, other pesticides are allowed for:3

  • biting or stinging insects, and stinging plants
  • insects and animals that spread disease
  • pests that threaten the health of trees or shrubs
  • state noxious weeds: thistles, Johnsongrass, shattercane and kudzu
  • four invasive plants the county has named: chameleon plant, Japanese knotweed, lesser celandine and wavyleaf basketgrass
  • indoor pests, applied around or near the foundation

Farms and golf courses are exempt.3

Warning signs

Straight after a pesticide goes on, signs go up in or along the edge of the treated area and stay for 48 hours. The approved sign reads “CAUTION Pesticide Application. Keep Off!”5 For organic products, the county suggests marking the sign “organic” so neighbours don’t report it by mistake.5

Hiring a lawn company

A company that applies pesticides for hire also needs a pesticide business licence from the Maryland Department of Agriculture.6 Ask whether they follow the county law and which products they’ll use. The county can issue warnings or fines for violations.4

Sources

  1. Pesticide Law, Montgomery County Department of Environmental Protection. Checked 29 Sep 2026.
  2. Purpose of the Pesticide Law, Montgomery County DEP. Checked 29 Sep 2026.
  3. Exemptions to the Pesticide Law, Montgomery County DEP. Checked 29 Sep 2026.
  4. Pesticide Law FAQs, Montgomery County DEP. Checked 29 Sep 2026.
  5. Signage requirements for pesticide applications, Montgomery County DEP. Checked 29 Sep 2026.
  6. Pesticide licensing and certification, Maryland Department of Agriculture. Checked 29 Sep 2026.

General information, not legal advice. Rules change, so check the source or your county before work starts.