Maryland residents must follow specific procedures when applying lawn fertilizer, according to a state law effective Oct. 1. The Fertilizer Use Act of 2011 is designed to prevent fertilizer from washing off lawns and into local waterways that empty into the Chesapeake Bay. The main ingredients in lawn fertilizer, phosphorus and nitrogen, are detrimental to Chesapeake Bay plant life and water quality.
While the law was signed in 2011, its onset was delayed in order to give lawn care companies time to comply with the requirement that all lawn care professionals receive state certification in fertilizer application.
“Cleaning up the Chesapeake Bay is everyone’s responsibility,” said Maryland Secretary of Agriculture Buddy Hance. “We are counting on homeowners and do-it-yourselfers to join Maryland farmers as full partners in the Bay cleanup.”
What the new law says
The new law mandates homeowners and lawncare professionals apply fertilizer according to these procedures:
1. First and foremost, test your soil.
Does your lawn really need fertilizer? A soil test can tell you. It will measure your soil for nutrients, pH and organic matter. You can do it yourself or take a sample and send it to a recommended lab for about $10. Consider a soil test as a money-saver; if your lawn truely does need fertilizer, you won't want to buy (or apply) too much.
2. Don't use phosphorus unless truly needed.
The new law bans the sale of fertilizers containing phosphorus with a few exceptions. Starter fertilizer may contain phosphorus because it helps grass take root in newly seeded lawns, but it's still a good idea to test your soil before applying it to see if it's really necessary.
3. Apply fertilizer at specific times.
Homeowners are now prohibited from applying fertilizer anytime the ground is frozen and from Nov. 15 and March 1. If you fertilize before the ground freezes, plants will store the nutrients in their roots all winter and have strength stored up for the spring.
4. Do not apply near water.
The closer you are to a waterway, the less distance the fertilizer has to travel before washing into the Chesapeake Bay. Fertilizer should not be applied within 15 feet of waterways, and this number is reduced to 10 feet if you are using certain fertilizer application tools.
5. Read labels and take it seriously.
Turfgrass is the largest-grown crop in Maryland, taking up nearly double the acreage as corn, according to the Bay Journal. Learn how to manage your turfgrass responsibly. Start with tips from the Maryland Department of Agriculture.
Why is fertilizer harmful?
Fertilizer often washes off lawns when it rains, entering into storm drains and eventually, the Chesapeake Bay. Once in the Bay, two of the main ingredients in fertilizer, phosphorus and nitrogen, feed algae and encourage it to grow. (This is not surprising, since these nutrients also encourage grass to grow.)
Large amounts of algae, known as "algal blooms," prevent sunlight from reaching underwater plants. These plants maintain the water's oxygen levels and serve as a home and a food source for Bay creatures.
About 14 percent of the nitrogen and 8 percent of the phosphorus pollution enter the Bay by washing off urban and suburban surfaces such as lawns, according to the Chesapeake Bay Commission.