The winter blackout
Don’t put fertilizer on a lawn between November 16 and March 1. Lawn care companies get a short extra window: from November 16 to December 1 they can apply up to half a pound of nitrogen per 1,000 square feet.1
At any time of year, don’t fertilize frozen ground or when heavy rain is forecast.1
Phosphorus needs a soil test
You can use phosphorus on an established lawn only if a soil test shows it needs it. The exception is a new lawn, or one you’re patching or renovating.1
Keep it away from water
Keep fertilizer 10 to 15 feet away from streams, ponds and other waterways.1
Hiring a lawn company
Anyone you pay to fertilize your lawn must be certified and licensed by the Maryland Department of Agriculture, and renew every year.1 Ask for their certification before they start. Listings on this site show when we’ve checked it.
When to fertilize
| Your grass | Best time | Most nitrogen a year, per 1,000 sq ft |
|---|---|---|
| Tall fescue, Kentucky bluegrass | Late summer into autumn | 2.7 lb |
| Fine fescue | Late summer into autumn | 1.4 lb |
| Zoysia | Late spring into summer | 1.8 lb |
| Bermudagrass | Late spring into summer | 2.7 lb |
The University of Maryland also says to test your soil rather than guess, and to leave mulched grass clippings on the lawn.2
Sources
- Maryland Lawn Fertilizer Law, Maryland Department of Agriculture. Checked 29 Sep 2026.
- Maintaining an established lawn, University of Maryland Extension. Checked 29 Sep 2026.
General information, not legal advice. Rules change, so check the source or your county before work starts.
