Outdoor

When should I fertilize my lawn? A schedule by grass type

By Nazrul Islam. Updated October 11, 2026.

Which type of grass do you have?

• Cool-season grasses grow best in spring and fall. They include Kentucky bluegrass, tall fescue, perennial ryegrass and fine fescue. They dominate the northern half of the US.
• Warm-season grasses grow best in summer heat and go brown and dormant in winter. They include Bermuda, zoysia, St. Augustine and centipede. They dominate the South.

Feed grass while it actively grows, and most heavily in its best season.

When to fertilize cool-season grass

Fall is the main feeding season. Purdue Extension says to apply most of the year’s nitrogen from late summer through autumn. That timing helps the lawn recover from summer, thicken up and prepare for winter.

Purdue turf scientists call September a crucial month. They recommend about 1 lb of nitrogen per 1,000 sq ft in September for almost all cool-season turf, using a fertilizer with 25–50% slow-release N. Purdue adds that newer research suggests a September feeding “may minimize the need for typical late October or November applications.”

Many extension programs also add a late-fall feeding. Purdue’s guide describes it this way:

• Late August to early November: up to 1 lb N per 1,000 sq ft per month.
• Early October to early December: 0.5 to 0.75 lb N per 1,000 sq ft about every three weeks, using mostly water-soluble nitrogen. Stop when the ground freezes.
• Spring: lighter rates, ideally slow-release, to avoid a flush of soft growth.
• Summer: little or none, unless you water often or bag clippings.

In the Carolinas, Clemson HGIC schedules tall fescue feedings in the Piedmont and Mountain areas in February, September and November.

When to fertilize warm-season grass

Warm-season lawns need nitrogen while they grow, which means late spring through summer.

Texas A&M AgriLife says to make the first application after the second mowing of actual grass, not weeds. That is usually about 6 weeks after the average last spring frost.

The last application should go down no later than 6 weeks before the expected first fall frost. Texas A&M gives sample cutoffs:

Late nitrogen keeps the grass pushing tender growth as it should be hardening off. Clemson notes that potassium in late August to mid-September may improve winter hardiness instead.

Centipede is the exception to “more is better.” Clemson says more than 2 lb N per 1,000 sq ft per year is not normally recommended, because it can lead to centipede decline.

Lawn fertilizer schedule by grass type

Approximate windows based on Purdue, Clemson, Texas A&M and UF/IFAS guidance; follow your state extension.

Purdue’s annual totals for cool-season lawns are 1–3 lb at low maintenance, 2–4 lb at moderate and 3–5 lb at high maintenance with irrigation. Shaded lawns should get no more than 2 lb per year.

How much fertilizer per 1,000 square feet?

The standard dose is about 1 lb of actual nitrogen per 1,000 sq ft per application. Purdue sets 1 lb as the maximum for water-soluble (quick-release) nitrogen. Up to 2 lb is acceptable only when more than half the nitrogen is slow-release. Texas A&M recommends single applications of 1 lb or less, at least 45 to 60 days apart.

UF/IFAS is stricter for Florida lawns. It caps quick-release nitrogen at 0.7 lb per 1,000 sq ft per application, and slow-release up to 2 lb per application in spring and summer and 1 lb in fall and winter.

How to calculate fertilizer from the bag numbers

The three numbers on the bag (N-P-K) are percentages by weight. The first number is nitrogen.

Formula:

Pounds of product per 1,000 sq ft = target lb of N ÷ (N% ÷ 100)

Worked example with 24-0-11:

1 lb N ÷ 0.24 = 4.17 lb of product per 1,000 sq ft (about 4.2 lb)

For a 5,000 sq ft lawn: 4.17 × 5 = 20.8 lb of 24-0-11.

To find coverage per bag, multiply bag weight by N%. Texas A&M’s example: 40 lb of 16-4-8 × 0.16 = 6.4 lb N, enough for 6,400 sq ft at 1 lb N per 1,000 sq ft.

Should you get a soil test first?

Yes. UF/IFAS calls a soil test “by far” the best start to a fertilization program. Texas A&M suggests testing every 2 to 3 years through your county extension office.

A soil test tells you whether you need phosphorus or potassium at all. Without a test, UF/IFAS suggests a phosphorus-free blend such as 15-0-15 for Florida lawns.

Is phosphorus lawn fertilizer restricted?

In some states, yes. Minnesota bans phosphorus fertilizer on lawns and turf unless a soil or tissue test shows a need, or you are establishing a new lawn from seed or sod. A zero middle number on the bag means phosphorus-free.

Other states and cities may have their own rules, so check with your county extension office.

Fertilizer safety and water-quality rules

• Don’t fertilize frozen or dormant lawns. Purdue says not to apply fertilizer in winter or on frozen soil. It also warns against feeding dormant or severely drought-stressed turf.
• Keep it off hard surfaces. Sweep or blow granules from sidewalks, driveways and streets back onto the grass. Minnesota requires spills on pavement to be cleaned up immediately.
• Keep it away from water. Excess nitrogen and phosphorus can reach streams, lakes and groundwater. Avoid spreading next to ponds, ditches and storm drains.
• Water it in. Quick-release nitrogen can burn leaves, so Purdue advises watering it into the turf.

Quick answers

What month should I fertilize my lawn? For cool-season grass, September is the most important month. For warm-season grass, feed from about May through August, starting after the lawn needs its second mowing.

Is it too late to fertilize in November? Not for cool-season lawns before the ground freezes. Purdue allows 0.5 to 0.75 lb N per 1,000 sq ft into early December. For warm-season lawns, it is usually too late.

How much 24-0-11 do I need per 1,000 sq ft? About 4.2 lb delivers 1 lb of nitrogen, because 1 ÷ 0.24 = 4.17.

Should I fertilize Bermuda grass in the fall? Only early fall. Texas A&M says the last application should be at least 6 weeks before your first expected frost.