Maryland’s fertilizer law is designed to protect streams and the Chesapeake Bay from runoff by banning fertilizer containing phosphorus and limiting how much fertilizer you can apply annually. You also can’t fertilize between Nov. 15 and March 1.
Excess nutrients from golf courses, parks, and lawns wash into the streams and the Chesapeake Bay. Fertilizer promotes algae growth, which prevents sunlight and oxygen from reaching the grass and threatens aquatic life.
Key takeaways
Choose the right fertilizer: Maryland’s fertilizer law bans fertilizers containing phosphorus.
Fertilize at the right quantity: You cannot apply more than 0.9 pounds of total nitrogen per 1,000 square feet of lawn, nor more than 2.5 pounds of fertilizer per 1,000 square feet annually.
Fertilize at the right time: The law restricts using fertilizer between Nov. 15 and March 1.
What kind of fertilizer is allowed in Maryland?
Maryland’s fertilizer law, which took effect in 2013, prohibits using fertilizers containing phosphorus. Most Maryland lawns have sufficient phosphorus, but if your soil test indicates a deficiency, you can add it. You can also apply phosphorus when establishing or renovating your lawn.
All fertilizer products are labeled with three numbers that represent the plant nutrients:
- Nitrogen (N) helps your grass grow and gives it a dark green appearance.
- Phosphorus (P) encourages strong root growth.
- Potassium (K) makes the grass more resistant to diseases, insects, and drought.
How much fertilizer is allowed?
The law prohibits applying more than 0.9 pounds of total nitrogen per 1,000 square feet each time you fertilize. It also restricts applying more than 2.5 pounds of fertilizer a year for 1,000 square feet.
Further, at least 20% of the fertilizer must be slow-release. Quick-release fertilizers promote rapid growth but can damage your grass if you don’t use them correctly. We recommend using quick-release fertilizers only on new lawns.
Use a drop spreader or broadcast spreader to apply fertilizer evenly. A drop spreader distributes fertilizer exactly where you want it and in the proper amount, while a broadcast spreader distributes fertilizer widely in all directions. The latter is ideal for large yards.
Fertilize at the right time
Maryland’s fertilizer law restricts using fertilizer between Nov. 15 and March 1 to prevent rainwater from washing fertilizer into estuaries.
Every grass type has different needs and preferences and requires fertilization at different times of year. Maryland sees warm summers and cool winters, which is ideal for both cool- and warm-season grasses.
Cool-season grasses: Kentucky bluegrass and tall fescue require around 2.7 pounds of nitrogen annually, while fine fescue requires 1.4 pounds. Apply the first round of fertilizer from May to early June, the second in September, and the last from October to mid-November.
Warm-season grasses: Bermudagrass requires around 2.7 pounds of nitrogen annually, while Zoysiagrass requires 1.8 pounds. Apply the first round of fertilizer from May to early June and the second from June to July.
Follow the lawn fertilizer schedule provided by the University of Maryland to fertilize your lawn correctly. Also, check out our guide on month-to-month Maryland lawn care schedule.
Other requirements
Additional regulations included in Maryland’s lawn fertilizer law include:
- Avoid applying fertilizers within 15 feet of waterways.
- Refrain from fertilizing if heavy rain is forecasted.
- Don’t fertilize to de-ice.
- Keep fertilizer away from driveways, sidewalks, and other impervious surfaces. If any fertilizer lands on them, sweep it back onto the grass or clean it up.
FAQs
Should I follow my city’s lawn fertilizer law or Maryland’s?
Maryland’s fertilizer law supersedes any city law. However, city or county ordinances usually align with the state law and don’t contradict it.
Can I fertilize by hand?
Yes, but it isn’t a good idea. Use a drop or broadcast spreader to apply fertilizer evenly.
What are the best organic fertilizers?
Here are some of the best organic fertilizers for your Maryland lawn that don’t contain phosphorus:
- Compost
- Worm castings
- Animal manure
- Kelp and seaweed
- Alfalfa
- Corn gluten meal
When to hire a professional
Maryland’s fertilizer law aims to prevent fertilizer runoff into the Chesapeake Bay. If you need help with lawn fertilization or any lawn maintenance activities, contact Lawn Love and let our pros take over.
Main Image Credit: Jackson Collins House / Acroterion / Wikimedia Commons / CC BY-SA 4.0
