Protect Local Waterways by Following Maryland’s Lawn Fertilizer Law

Lawn Fertilizer Blackout Dates End March 1

ANNAPOLIS, MD – The Maryland Department of Agriculture reminds lawn care professionals and homeowners to follow the state’s lawn fertilizer law as warmer weather approaches. Fertilizer products containing nitrogen and phosphorus may be applied to lawns beginning March 1 as long as the ground is not hard frozen or snow-covered and heavy rain is not expected.

Maryland’s Lawn Fertilizer Law is designed to prevent excess nutrients from entering the Chesapeake Bay and local waterways, and requires that lawn care professionals be licensed and certified by the department to apply fertilizer. Nutrients, primarily nitrogen and phosphorus, are key ingredients in lawn fertilizer. When it rains, fertilizer applied to lawns can wash into nearby storm drains and streams that flow into the Chesapeake Bay. Once in our waterways, nutrients contribute to algae blooms that block sunlight from reaching bay grasses, rob the water of oxygen, and threaten underwater life.

Best management practices for the health of your lawn and the Chesapeake Bay:

• Skip the spring fertilizer, especially if your lawn is healthy. Fertilizing lawns in spring promotes excessive top growth at the expense of roots.
• Sharpen lawnmower blades. A dull blade tears and weakens the grass, opening it up to disease. Many local hardware stores or garden shops can sharpen your blade for you.
• Raise the cutting height of the mower. Taller grass shades out weeds and needs less water. A three-inch cut length is ideal for most lawns.
• Leave grass clippings on the lawn. They provide free fertilizer all season long.

If fertilizer is necessary:

• Follow the directions on the fertilizer bag.
• Learn about soil testing. For seasonal and yearly fertilizer recommendations, visit: extension.umd.edu/hgic/plants/lawns
• Do not apply phosphorus to lawns unless a soil test indicates that it is needed.
• Clean up any fertilizer on sidewalks or other impervious surfaces.
• Keep fertilizer applications 10 to 15 feet away from waterways.
• Do not apply fertilizer if heavy rain is expected.

The lawn fertilizer law applies to urban sources, including golf courses, parks, recreation areas, businesses, and home lawns. Citizens can verify that their lawn care provider is certified by visiting the department’s website. For more information, visit mda.maryland.gov/fertilizer.

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