Noxious Weed Control

Noxious Weeds in Maryland

Prohibited noxious weeds are annual, biennial, or perennial plants that the Secretary of Agriculture has designated as having adverse or threatening affects to agricultural production throughout the State. There are currently eight plant species under the Noxious Weed Regulations that have been designated as noxious weeds in Maryland.  Maryland Weed Control Law requires landowners to eradicate or control noxious weeds on their land. Control methods include mowing, cultivating, or treating with an approved herbicide. 

Noxious weeds in Maryland include: ​​​​​​​​​​​​​​

• Bull thistle, Cirsium vulgare, designated in 1984 
• Canada thistle, Circium arvense, designated in 1984
• Johnsongrass, Sorghum halepense, designated in 1969
• Musk/knodding thistle, Carduus nutans, designated in 1984
• Palmer amaranth, Amaranthus palmeri, designated in 2020
• Plumeless thistle, Carduus acanthoides, designated in 1984
• Shattercane, Sorghum bicolor, designated in 1987
• Tall waterhemp​, Amaranthus tuberculatus, A. rudis, designated in 2020

What the Weed Control Program Does

The MDA Weed Control Program:

• Surveys public and private lands for noxious weeds.
• Enforces the Maryland Weed Control Law. 
• Assists farmers and landowners in the battle against designated noxious weeds.
• Enters into an agreement with participating counties (see table below) to provide: 
  • Technical assistance to county weed control coordinators and landowners.
  • Facilitate targeted herbicide spraying along State Highway Administration right-of-way.  

Resources

• Maryland Noxious Weed ID Brochure - PDF - 4.55 MB
• ​​University of Maryland Extension Offices

Noxious Weed Factsheets

• Bull thistle - PDF - 3.11 MB
• Canada thistle - PDF - 2.24 MB
• Johnsongrass - PDF - 2.89 MB
• Musk thistle - PDF - 4.19 MB
• Palmer amaranth - PDF - 2.07 MB
• Plumeless thistle
• Shattercane - PDF - 2.33 MB
• Tall waterhemp - PDF - 7.46 MB

Noxious Weed Reporting

To report a noxious weed, please e-mail the following information to: [email protected].

• Subject Line: Report a Noxious Weed.
• County.
• Name.
• Contact Information: Email and/or phone number.
• Detailed location (cross streets, address, GPS coordinates, etc).
• Noxious weed(s) present. 
• Description of the problem.
• Please attach photo(s).

All reports will be handled confidentially.

Weed Control Contacts

Maryland Department of Agriculture

For weed identification, enforcement questions and other inquiries:

County Weed Control

For local weed-control questions, county-specific assistance, and coordination of weed-control activities along State Highways:

University of Maryland

For specific herbicide and management recommendations, weed identification, and organic weed-management options: