When to Aerate, State by State

Pull soil cores to relieve compaction — timed to peak growth. The right week depends on where you live — every window below comes from that state's own climate record.

Cool-season lawns: why then

Core-aerate cool-season lawns in early fall, when the grass is entering its strongest growth phase and can fill the holes quickly — it pairs naturally with overseeding, since seed-to-soil contact in the core holes is excellent. Aerating in summer stresses the lawn; aerating in spring works but opens soil right as crabgrass germinates.

Warm-season lawns: why then

Aerate warm-season lawns in late spring to early summer, once the lawn is fully green and growing fast — that’s when Bermuda and Zoysia recover quickest and the holes close in weeks. Never aerate a warm-season lawn while it is dormant or just waking up; it cannot heal the disturbance.

State	Region	Cool-season	Warm-season
Alabama	Warm-season	—	Mar 21 – May 19
Alaska	Cool-season	Jul 8 – Sep 7	—
Arizona	Transition zone	Nov 4 – Nov 2	Feb 2 – Jul 30
Arkansas	Transition zone	Sep 1 – Sep 26	Apr 18 – May 30
California	Transition zone	Oct 15 – Nov 5	Feb 9 – Apr 7
Colorado	Cool-season	Aug 9 – Sep 8	—
Connecticut	Cool-season	Aug 27 – Sep 12	—
Delaware	Transition zone	Sep 5 – Sep 20	May 2 – Jun 2
District of Columbia	Transition zone	Sep 2 – Sep 17	May 3 – May 31
Florida	Warm-season	—	Feb 14 – Apr 7
Georgia	Warm-season	—	Mar 30 – May 19
Hawaii	Warm-season	—	Mar 10 – Apr 7
Idaho	Cool-season	Aug 2 – Sep 6	—
Illinois	Cool-season	Aug 18 – Sep 21	—
Indiana	Cool-season	Aug 22 – Sep 26	—
Iowa	Cool-season	Aug 8 – Sep 5	—
Kansas	Transition zone	Aug 23 – Sep 14	May 9 – Jun 11
Kentucky	Transition zone	Aug 29 – Sep 25	Apr 28 – Jun 8
Louisiana	Warm-season	—	Mar 1 – Apr 25
Maine	Cool-season	Aug 2 – Aug 31	—
Maryland	Transition zone	Aug 25 – Oct 7	Apr 20 – Jun 10
Massachusetts	Cool-season	Aug 9 – Sep 25	—
Michigan	Cool-season	Aug 11 – Sep 16	—
Minnesota	Cool-season	Aug 7 – Sep 1	—
Mississippi	Warm-season	—	Mar 18 – May 16
Missouri	Transition zone	Aug 28 – Sep 20	Apr 29 – May 30
Montana	Cool-season	Aug 2 – Aug 17	—
Nebraska	Cool-season	Aug 4 – Sep 6	—
Nevada	Transition zone	Jul 20 – Oct 26	Feb 21 – Jul 24
New Hampshire	Cool-season	Aug 4 – Aug 27	—
New Jersey	Cool-season	Aug 29 – Oct 7	—
New Mexico	Transition zone	Aug 7 – Sep 29	Apr 9 – Jul 9
New York	Cool-season	Aug 16 – Oct 6	—
North Carolina	Transition zone	Sep 1 – Sep 24	Apr 25 – Jun 1
North Dakota	Cool-season	Aug 1 – Aug 16	—
Ohio	Cool-season	Aug 25 – Sep 28	—
Oklahoma	Transition zone	Sep 3 – Sep 20	Apr 28 – May 30
Oregon	Cool-season	Jul 22 – Oct 17	—
Pennsylvania	Cool-season	Aug 24 – Oct 3	—
Rhode Island	Cool-season	Aug 31 – Sep 15	—
South Carolina	Warm-season	—	Mar 4 – May 23
South Dakota	Cool-season	Aug 7 – Aug 24	—
Tennessee	Transition zone	Aug 29 – Oct 2	Apr 13 – Jun 6
Texas	Warm-season	—	Mar 2 – May 19
Utah	Cool-season	Aug 3 – Sep 26	—
Vermont	Cool-season	Aug 10 – Aug 31	—
Virginia	Transition zone	Sep 2 – Sep 28	Apr 26 – May 29
Washington	Cool-season	Aug 5 – Oct 3	—
West Virginia	Transition zone	Aug 24 – Sep 11	May 14 – Jun 21
Wisconsin	Cool-season	Aug 10 – Sep 7	—
Wyoming	Cool-season	Jul 2 – Aug 17	—

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 Aerate, State by State

Cool-season lawns: why then

Warm-season lawns: why then

Other timing questions