How to read a fertilizer bag

Every fertilizer bag shows three numbers, like 20-0-5. They are the percentages of nitrogen (N), phosphate (P) and potash (K). Lawns mostly need nitrogen, and your soil test tells you whether they need the rest.

Decoding the bag

• A 50 lb bag of 20-0-5 contains 10 lb of nitrogen
• Look for "slow-release" or "water-insoluble" nitrogen; it feeds more evenly and is less likely to burn
• The middle number is often 0 because many lawns don't need phosphorus, and some states restrict it on lawns

How much

• Many extension services suggest no more than about 1 lb of nitrogen per 1,000 sq ft in a single application
• Follow the spreader setting on the bag for your spreader model
• Measure your lawn area once and write it down

Protect water

• Sweep fertilizer off driveways, sidewalks and streets back onto the lawn
• Don't fertilize before heavy rain or on frozen ground
• Leave an unfertilized strip next to ponds and streams
• Check local rules: some places set blackout dates or ban phosphorus

General information. Always follow the product label. Reliable Service Crew isn't paid by any brand or lawn company.