When to Fertilize Your Lawn: A Schedule by Grass Type and Climate

The best time to fertilize depends on your grass. Cool-season lawns (Kentucky bluegrass, tall fescue, perennial ryegrass) get their most important feeding in late summer to early fall, a lighter one in spring, and little or none in summer. Warm-season lawns (Bermuda grass, zoysia, St. Augustine) are fed from spring green-up through summer, and the last nitrogen should go down at least six weeks before your first fall frost.

Below, we turn that rule into dates for 20 Southern cities from NOAA frost normals, and check them against Texas A&M’s own.

The lawn fertilizer schedule at a glance

Check your grass type first (our guide to cool-season vs. warm-season grass shows how). Amounts are pounds of actual nitrogen per 1,000 sq ft for a moderately fed lawn with clippings left on.

The cool-season column is Purdue Extension’s moderate-maintenance program;² the warm-season column follows Texas A&M AgriLife Extension.⁴ On a lower budget, drop the optional feedings.

Cool-season lawns: make the fall feeding count

Purdue’s turf specialists say bluegrass, fescue and ryegrass benefit most when most of the year’s nitrogen goes down from late summer through autumn, with less in spring.² Illinois Extension says it plainly:

This is considered the optimal fertilizer timing for a cool-season lawn.

The exact weeks shift with latitude:

Sources: Illinois Extension’s lawn fertilizing guide³ and Purdue’s Fertilizing Established Cool-season Lawns (AY-22-W).² UW–Madison Extension makes the same call for Wisconsin: early September is “a key time to add nitrogen” (Ideal Timing for Fertilizing Lawns).¹² If your state publishes its own calendar, use it.

Spring: later and lighter than you might think

Purdue recommends slow-release products in spring to limit excess growth.² In central Illinois the spring window is early to mid-May, but crabgrass preventer goes down in early April, so Illinois calls weed-and-feed products a compromise in timing.³ Our guide to when to apply pre-emergent covers crabgrass timing separately.

The late-season feeding (the “winterizer”)

Illinois times the last feeding about a week after the final mowing.³ Our guide to when to stop mowing your lawn gives normal-year last-mow dates by city. Purdue prefers mostly water-soluble nitrogen from early October until early December, or until the ground freezes, and notes that extra phosphorus and potassium are unnecessary if a soil test shows enough.²

Warm-season lawns: feed after green-up, stop six weeks before frost

Bermuda grass, zoysia, St. Augustine and centipede grass grow in the heat and sleep through winter. Texas A&M AgriLife Extension’s Fertilizing Texas Lawns (E-436) ties both ends of their season to frost dates.⁴ The first feeding comes after the second mowing of grass (not weeds), usually about six weeks after the average last spring frost. The last nitrogen goes down early enough for the lawn to use it before winter:

no later than 6 weeks before the expected autumn frost date

We applied both rules to median frost dates from the NOAA station nearest each of 20 Southern ZIP codes.¹

The spring date is an estimate; the second mowing is the real signal. In Houston, New Orleans, Jacksonville and Tucson a fall frost does not come every year, so treat the median as a softer guide. For any other ZIP code, look up your frost dates and count six weeks either way.

Do our dates match Texas A&M’s?

Texas A&M publishes cut-off dates for five Texas frost zones.⁴ Against our station dates for 15 Texas cities, seven fell within a week and the median gap was eight days. The biggest gaps were downtown Dallas (+17 days) and downtown Houston (+29 days), where city-center stations run warm.

Texas A&M uses one average frost date per region; ours are per station. When they disagree, use the earlier date. So a Dallas lawn of common Bermuda grass gets its first feeding in mid-April after two mowings, more every 45–60 days, and the last by October 1.

Georgia and North Carolina are more cautious

The six-week rule is a latest date. A UGA Extension county office in South Georgia advises feeding Bermuda grass and zoysia only until mid-August, avoiding fall feedings on Bermuda grass, and skipping fall nitrogen entirely on centipede grass.⁷ NC State Extension limits Bermuda grass to half a pound of nitrogen in September, or four weeks before the first expected frost, as a low-nitrogen, high-potassium product, to limit spring dead spot disease.⁶ Where your state publishes advice like this, follow it.

In the transition zone, feed the grass, not the state

From Kansas and Missouri east to Virginia and North Carolina, both kinds of grass grow side by side. A tall fescue lawn in Charlotte follows the cool-season schedule, with its main feeding in early fall; the Bermuda grass lawn next door follows the warm-season one and stops in September.

How much fertilizer: the nitrogen math

Rates are pounds of nitrogen (N) per 1,000 sq ft, not pounds of product. The first number on the bag is percent nitrogen by weight (see our glossary entry on N-P-K). Illinois, Purdue and Penn State use the same two steps:³

1. Divide the nitrogen rate you want by the first number on the bag, written as a decimal. That gives pounds of product per 1,000 sq ft.
2. Multiply by your lawn area in thousands of square feet.

Penn State’s example: 1.0 ÷ 0.26 = 3.8 lb of 26-5-10 per 1,000 sq ft.⁵

Yearly needs depend on the grass and how green you want it:

Cool-season row: Purdue;² warm-season rows: Texas A&M.⁴ Purdue says shaded lawns need up to 50% less, lawns with bagged clippings 25–50% more, and lawns fed for over 10 years less. Never put down more than 1 lb of quick-release nitrogen per 1,000 sq ft at once; products more than half slow-release can go to 2 lb.²

When not to fertilize

Do not apply fertilizer to dormant or severely drought-stressed turf.

Purdue adds: not in winter or on frozen soil.² Also skip midsummer for cool-season grass, anything after your cut-off date for warm-season grass, and right before a downpour.

Some places make it law. New Jersey homeowners may not apply nitrogen or phosphorus after November 15 and before March 1 (potassium-only products and lime are allowed), according to Rutgers’ guide to the state fertilizer law.⁸ Minnesota bans phosphorus fertilizer on lawns unless a soil, tissue or other approved test from the past three years shows a need, or you are establishing a new lawn from seed or sod in its first growing season.⁹ Pinellas County, Florida bans nitrogen and phosphorus from June 1 to September 30, at any time the National Weather Service has a flood, severe thunderstorm, tropical storm or hurricane watch or warning in effect, and whenever 2 inches of rain or more is forecast within 24 hours.¹⁰

How to apply it so it ends up in the grass

• Test the soil first. A lab test shows whether you need phosphorus, potassium or lime; there is no reliable soil test for nitrogen.²
• Use a rotary (broadcast) spreader for more even coverage than a drop spreader.
• Water it in. Quick-release nitrogen can burn leaves; Purdue² and UGA⁷ both say to water fertilizer in.
• Sweep up strays from sidewalks and driveways back onto the grass.
• Mow high and leave the clippings: 2.5 inches or taller, per Purdue. See our mowing and watering guides.

New seedings follow a different plan, with starter fertilizer at seeding. Our guide on when to overseed your lawn covers it, and the seeding section has the rest.

Related guideWhen to Overseed Your Lawn: The Last Safe Day Where You Live

Your next step

Put two dates in your calendar: your main feeding and your last safe feeding date. Browse the fertilizing section and our other lawn care guides; the methodology page explains how our frost dates are calculated.