The Best Lawn Fertilizer

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Lawn fertilizer aisles are crowded with bags that look alike. The numbers on the front, how fast the nitrogen releases and when the bag is meant to go down matter far more than the brand.

I look after my own lawn, and I read fertilizer labels the way I read specs in my workshop: what’s actually in it, and how much per square foot. The picks below are based on the makers’ published specs and owner reviews. Timing and rates come from university extension services.

The picks

What the numbers mean

Every bag lists three numbers, N-P-K: the percentage of nitrogen, phosphate and potash by weight.

• Nitrogen (N) drives green color and leaf growth. It’s the main thing lawns need.
• Phosphorus (P) helps new roots. Purdue Extension says most established lawns already have enough, so phosphorus-free fertilizer suits them. It matters most when seeding.
• Potassium (K) supports stress tolerance. Fall products often carry more of it.

A soil test is the only reliable way to know whether your soil needs phosphorus or potassium. Your county extension office can run one.

How much product to apply

Purdue Extension says to apply generally no more than 1 lb of actual nitrogen per 1,000 sq ft per application, except for organic and slow-release products. To work it out:

1. Multiply bag weight by the first number. A 17 lb bag of 30-0-3 holds about 5 lb of nitrogen.
2. At 1 lb per 1,000 sq ft, that bag covers about 5,000 sq ft.

Most bags already list coverage, so you can skip the math. Just don’t go over the label rate.

Quick-release vs. slow-release

Purdue says quick-release nitrogen feeds for about 4 to 6 weeks and can injure turf at high rates. Slow-release nitrogen feeds for 6 to 8 weeks or longer and usually costs more. Missouri Extension notes that lawn fertilizers often contain 24 to 50% slow-release nitrogen. Look for “slow-release” or “water-insoluble nitrogen” on the label.

1. Scotts Turf Builder Lawn Food: best overall

The current Turf Builder Lawn Food is a 38-0-4 granular product with a mix of slow-release and quick-release nitrogen, per Scotts. One bag covers 4,000 sq ft at the standard Turf Builder rate, or 3,000 sq ft at the heavier Max Greening rate.

Scotts says it’s safe on all grass types at the standard rate, and to apply when daytime temperatures are consistently 60 to 90°F. Scotts suggests feeding 4 times a year and limits the Max Greening rate to two applications per year. It also says not to use the Max Greening rate on centipede or zoysia.

Why it’s the pick:

• Zero phosphorus suits established lawns.
• Mixed nitrogen gives quick color plus longer feeding.
• Easy to find, with spreader settings on the bag.

What to watch: Scotts lists different bag weights in different places on the same page, so check the bag. Residents of Maryland, Pennsylvania, New Jersey and Virginia get a lower state-specific rate on the label and a limit of 3 applications a year.

2. Pennington Full Season Lawn Fertilizer 32-0-5: best slow-release

Pennington Full Season uses polymer-coated urea and says it feeds for up to 4 months, per Pennington. The 11.2 lb bag covers up to 4,000 sq ft and the 33.6 lb bag covers 12,000 sq ft. It’s labeled for any grass type and meant for spring application.

Why it’s a good choice:

• Coated nitrogen releases gradually, so fewer feedings.
• Zero phosphorus.
• Large bag for bigger lawns.

What to watch: Pennington says to mow and water 1 to 2 days before applying. It’s not sold in Hawaii or South Dakota. Long-release products are slower to show color than quick-release ones.

3. Scotts Turf Builder WinterGuard Fall Lawn Food: best fall fertilizer

WinterGuard is a 32-0-10 granular fall feeding. Scotts says to apply once a year in fall, from August through November, and that it covers 4,000 sq ft per bag, per Scotts. The extra potassium is aimed at helping lawns recover from summer and prepare for winter.

Why it’s a good choice:

• Fall is the most important feeding for cool-season lawns.
• Higher potash than an everyday lawn food.
• Scotts says it can go on wet or dry grass.

What to watch: fall feeding is meant for cool-season grasses. Warm-season lawns heading into dormancy generally shouldn’t get late-season nitrogen. Bag weight isn’t listed on the product page.

4. Jonathan Green Winter Survival: fall pick with more potash

Winter Survival is a 10-0-20 fall fertilizer with polymer-coated urea, urea, potash and iron, per Jonathan Green. The 15 lb bag covers up to 5,000 sq ft and the 45 lb bag up to 15,000 sq ft. Jonathan Green says it can go down the same day as fall seeding or sodding.

Why it’s a good choice:

• High potassium for root and stress support.
• Partly coated nitrogen for gentler feeding.
• Works alongside fall overseeding.

What to watch: much lower nitrogen than WinterGuard, so less green-up. The page lists two slightly different application windows, roughly late August to mid-November.

5. Jonathan Green Organic Lawn Food: best organic

This 10-0-1 organic fertilizer is made from feather meal, soybean meal, blood meal, sulfate of potash and calcium carbonate, per Jonathan Green. The 17 lb bag covers up to 5,000 sq ft and the 51 lb bag up to 15,000 sq ft. It can be applied in spring, summer or fall, and on the same day you seed or lay sod. Jonathan Green says it works on cool- and warm-season grasses.

Why it’s a good choice:

• Natural nitrogen sources release slowly.
• Safe to use when seeding, per the maker.
• Includes calcium, sulfur and iron.

What to watch: low nitrogen means you spread more product per square foot for the same feeding, and it costs more per pound of nitrogen. Organic products depend on soil microbes, so they’re slow in cool soil.

6. Scotts Turf Builder Southern Lawn Food FL: for Florida and Southern lawns

This is a 32-0-10 product for actively growing Southern lawns of any grass type, per Scotts. A 14.06 lb bag covers 5,000 sq ft, and Scotts says one application feeds for up to 3 months.

Why it’s a good choice:

• Formulated for Florida and other Southern lawns.
• Zero phosphorus with 10% potash.
• Covers 5,000 sq ft per bag.

What to watch: Scotts says to apply it only once a year, not in winter in North Florida, and not within a month of the first expected frost on warm-season grass. Check your county’s fertilizer rules before buying.

Fertilizer by grass type

Centipede is the one to be careful with. Clemson’s HGIC notes that too much nitrogen can cause decline and disease. UGA Extension suggests a 15-0-15 product for centipede and skipping fall feeding.

For timing in detail, see when to fertilize your lawn.

Spring product vs. fall product

You don’t need a different bag for every season, but the label hints at where a product fits.

Everyday lawn food (like Turf Builder 38-0-4 or Pennington 32-0-5) is high in nitrogen with a little potash. It suits spring and summer feedings on warm-season grass and the light spring feeding on cool-season grass.

Fall products (WinterGuard 32-0-10, Winter Survival 10-0-20) carry more potassium. They’re aimed at the early fall feeding on cool-season lawns, which Purdue’s turf program puts between Labor Day and Halloween.

Starter fertilizers contain phosphorus for new seed. Use them only when seeding, unless a soil test says otherwise.

A worked example

Say you have a 6,000 sq ft tall fescue lawn and want to apply 1 lb of nitrogen per 1,000 sq ft in early September.

• You need 6 lb of actual nitrogen.
• A 32% product contains 0.32 lb of nitrogen per pound of product.
• 6 divided by 0.32 is about 19 lb of product.

That’s roughly two of the 4,000 sq ft bags. In practice, read the coverage on the bag and use the spreader setting it lists. The math is only a check that the label rate fits your goal.

Granular vs. liquid

Granular fertilizer is easier to apply evenly over a whole lawn with a spreader, and it’s where you’ll find slow-release nitrogen. Liquid hose-end products green up quickly but feed for a shorter time and are harder to apply evenly over large areas. For most yards, granular is the better value. A good lawn spreader makes a bigger difference than the brand of fertilizer.

Weed and feed: should you buy it?

Combination products save a step but tie your fertilizer timing to your weed control timing. AgriLife Extension’s crabgrass advice notes that nitrogen-containing crabgrass preventers are meant for northern lawns. In Texas, it suggests using a preventer without nitrogen, because warm-season grass is mostly dormant when crabgrass sprouts. If you need crabgrass control, see best pre-emergent for lawns.

Applying fertilizer without problems

• Follow the label rate and spreader setting. More fertilizer doesn’t mean greener grass. It means burn and runoff.
• Sweep granules off hard surfaces back onto the lawn. Scotts says not to apply near water, storm drains or ditches.
• Skip it before heavy rain. Both Scotts and Pennington say not to apply when heavy rain is expected.
• Check local rules. Maryland Extension, for example, notes state law bans lawn fertilizer from November 15 to March 1.
• Water in if the label says so.

The lawn care calendar puts fertilizer in context with mowing, seeding and weed control.

My pick

For most lawns, Scotts Turf Builder Lawn Food is the simple choice: zero phosphorus, mixed-release nitrogen and clear coverage. If you’d rather feed less often, Pennington Full Season 32-0-5 is the slow-release option. Cool-season lawns get the most from a fall feeding with Scotts WinterGuard. Southern lawn owners should check their grass type first, especially centipede.