When to Fertilize, State by State

Feed when the grass can use it — fall for cool-season, summer for warm. The right week depends on where you live — every window below comes from that state's own climate record.

Cool-season lawns: why then

Cool-season lawns take most of their annual nitrogen in fall — the main feeding 4–8 weeks before first frost fuels root growth and next spring’s green-up without the disease-prone lushness of heavy spring feeding. A light spring application after green-up and an optional winterizer 2–4 weeks before frost round out the year. Heavy feeding in summer heat mostly feeds fungus.

Warm-season lawns: why then

Warm-season lawns feed during their growth engine: from full green-up (3–6 weeks after last frost) through late summer, roughly monthly at modest rates. The critical *stop* date matters as much as the start — nitrogen within 6–8 weeks of first frost pushes tender growth that winter kills.

State	Region	Cool-season	Warm-season
Alabama	Warm-season	—	Mar 14 – May 5
Alaska	Cool-season	Jul 12 – Sep 24	—
Arizona	Transition zone	Nov 8 – Nov 19	Jan 26 – Jul 16
Arkansas	Transition zone	Sep 5 – Oct 13	Apr 11 – May 16
California	Transition zone	Oct 19 – Nov 22	Feb 2 – Mar 24
Colorado	Cool-season	Aug 13 – Sep 25	—
Connecticut	Cool-season	Aug 31 – Sep 29	—
Delaware	Transition zone	Sep 9 – Oct 7	Apr 25 – May 19
District of Columbia	Transition zone	Sep 6 – Oct 4	Apr 26 – May 17
Florida	Warm-season	—	Feb 7 – Mar 24
Georgia	Warm-season	—	Mar 23 – May 5
Hawaii	Warm-season	—	Mar 3 – Mar 24
Idaho	Cool-season	Aug 6 – Sep 23	—
Illinois	Cool-season	Aug 22 – Oct 8	—
Indiana	Cool-season	Aug 26 – Oct 13	—
Iowa	Cool-season	Aug 12 – Sep 22	—
Kansas	Transition zone	Aug 27 – Oct 1	May 2 – May 28
Kentucky	Transition zone	Sep 2 – Oct 12	Apr 21 – May 25
Louisiana	Warm-season	—	Feb 22 – Apr 11
Maine	Cool-season	Aug 6 – Sep 17	—
Maryland	Transition zone	Aug 29 – Oct 24	Apr 13 – May 27
Massachusetts	Cool-season	Aug 13 – Oct 12	—
Michigan	Cool-season	Aug 15 – Oct 3	—
Minnesota	Cool-season	Aug 11 – Sep 18	—
Mississippi	Warm-season	—	Mar 11 – May 2
Missouri	Transition zone	Sep 1 – Oct 7	Apr 22 – May 16
Montana	Cool-season	Aug 6 – Sep 3	—
Nebraska	Cool-season	Aug 8 – Sep 23	—
Nevada	Transition zone	Jul 24 – Nov 12	Feb 14 – Jul 10
New Hampshire	Cool-season	Aug 8 – Sep 13	—
New Jersey	Cool-season	Sep 2 – Oct 24	—
New Mexico	Transition zone	Aug 11 – Oct 16	Apr 2 – Jun 25
New York	Cool-season	Aug 20 – Oct 23	—
North Carolina	Transition zone	Sep 5 – Oct 11	Apr 18 – May 18
North Dakota	Cool-season	Aug 5 – Sep 2	—
Ohio	Cool-season	Aug 29 – Oct 15	—
Oklahoma	Transition zone	Sep 7 – Oct 7	Apr 21 – May 16
Oregon	Cool-season	Jul 26 – Nov 3	—
Pennsylvania	Cool-season	Aug 28 – Oct 20	—
Rhode Island	Cool-season	Sep 4 – Oct 2	—
South Carolina	Warm-season	—	Feb 25 – May 9
South Dakota	Cool-season	Aug 11 – Sep 10	—
Tennessee	Transition zone	Sep 2 – Oct 19	Apr 6 – May 23
Texas	Warm-season	—	Feb 23 – May 5
Utah	Cool-season	Aug 7 – Oct 13	—
Vermont	Cool-season	Aug 14 – Sep 17	—
Virginia	Transition zone	Sep 6 – Oct 15	Apr 19 – May 15
Washington	Cool-season	Aug 9 – Oct 20	—
West Virginia	Transition zone	Aug 28 – Sep 28	May 7 – Jun 7
Wisconsin	Cool-season	Aug 14 – Sep 24	—
Wyoming	Cool-season	Jul 6 – Sep 3	—

Ranges span each state's featured cities — click your state for city-level windows, or jump straight to your ZIP with the lawn calendar lookup.

When to Fertilize, State by State

Cool-season lawns: why then

Warm-season lawns: why then

Other timing questions