Inexpensive Lawn Fertilizer Tips | Feed Your Lawn For Less

The lawn fertilizer aisle is a maze of colorful bags, each promising a lush green carpet for a price that keeps climbing. The good news: you do not need a single one of the expensive blends. A simple, $25 bag of ammonium sulfate delivers the nitrogen your grass actually needs, and a few minutes with a calculator can save you from wasting money—and product—on your yard. Here is exactly how to fertilize cheaply, effectively, and safely.

Why Most Lawn Fertilizer Is Overpriced

Many all-purpose lawn fertilizers contain phosphorus (the middle number in the NPK ratio) and potassium (the last number), which the typical lawn does not require. Unless a soil test has revealed a specific deficiency, you are paying for nutrients your grass cannot use. That extra phosphorus can also run off into waterways, making it an environmental liability, not a benefit. The most cost-effective approach is to target only what your lawn actually needs: nitrogen.

Ammonium Sulfate: The $25 Winner

Sta-Green’s 20-0-0 Ammonium Sulfate (or any generic ammonium sulfate nitrogen fertilizer) costs between $25 and $30 per bag. It contains 20 percent nitrogen and zero phosphorus or potassium, making it a pure, targeted feed for most lawns. For the average yard, this single product meets nearly all your seasonal fertilization needs without the markup of multi-nutrient blends.

How To Calculate The Right Amount

The Illinois Extension provides a straightforward formula for figuring out exactly how much fertilizer to spread so you do not underfeed or burn the grass. You want to apply between 0.5 and 1.0 pound of actual nitrogen per 1,000 square feet per application.

Your calculation in three steps:

1. Divide your target nitrogen rate (e.g., 0.5) by the decimal form of the nitrogen percentage in the bag (0.20 for a 20-0-0 product). That number is the pounds of product needed per 1,000 square feet.
2. Multiply that number by your lawn’s total square footage.
3. Divide that result by 1,000.

Example: For a 20-0-0 bag at a 0.5 lb/1,000 sq. ft. goal: 0.5 ÷ 0.20 = 2.5 pounds of fertilizer needed per 1,000 sq. ft. For a 5,000 sq. ft. lawn, that is 12.5 pounds total per application.

For a full roundup of the best budget-friendly bags and brands, check out our tested recommendations for cheap lawn fertilizer that work without the premium price tag.

Application Schedule That Saves Money

When you fertilize matters just as much as what you use. Applying fertilizer at the wrong time wastes product and can damage the grass.

For Cool-Season Grasses (Fescue, Bluegrass, Ryegrass)

• Spring: One application in early to mid-May provides nitrogen for growth after the winter dormancy.
• Late Summer / Early Fall: A second application between August 15 and September 15 is the most important feeding of the year for cool-season turf.
• Optional Winterizer: A third application in late October to early November helps root development.

No-fly zone: Avoid fertilizing cool-season lawns during the heat of summer. It stresses the grass and often feeds weeds instead.

For Warm-Season Grasses (Bermuda, Zoysia, St. Augustine)

• Spring: Apply after the grass is fully green and actively growing.
• Summer: One or two additional applications during the growing season.
• Stop by late summer: Fertilizing too late in the fall reduces winter hardiness.

Lawn Fertilizer Cost Comparison

Applying Fertilizer The Right Way

ScottsMiracle-Gro’s official guidance recommends a specific order to get even coverage without waste.

1. Water the lawn a few days before application so the soil is ready to absorb nutrients.
2. Choose your spreader type. A broadcast spreader covers open areas quickly. A drop spreader delivers precision around flower beds and edges. Broadcast spreaders can cost up to $300; handheld models start at $11.
3. Treat the perimeter first. Engage the side-shield (many Scotts broadcast spreaders call this EdgeGuard®) to keep product off driveways and sidewalks.
4. Fill the middle by walking back and forth in straight lines. Overlap slightly by turning two steps before you reach the previous pass.
5. For drop spreaders, start with two header strips at opposite ends of the lawn. Overlap wheel tracks by 0.5 feet for full coverage.
6. Never spread product by hand. It is almost impossible to get an even rate, and you risk burning the grass in concentrated spots.
7. Return unused product to the bag and store in a cool, dry place away from pets and children.

Spreaders vs. Price

Mistakes That Waste Money And Harm The Lawn

• Over-fertilizing: Applying more than 1.0 pound of nitrogen per 1,000 square feet in quick-release form risks burning the grass and wasting product.
• Using excess phosphorus: Most lawns do not need it. Buying a 10-10-10 blend when a soil test shows adequate phosphorus means paying for a nutrient you flush into the storm drain.
• Fertilizing cool-season grass in summer: The grass is semi-dormant and cannot use the nitrogen. The weeds can and will.
• Skipping a soil test: Testing pH and NPK levels for about $15 removes the guesswork. Without it, you are buying fertilizer in the dark.
• Mowing too short: Keep cool-season grass at 4 inches. Shorter grass loses root depth, invites weeds, and needs more fertilizer to compete.

Decide Your Lawn’s Season Plan