When to Fertilize Your Lawn: State-by-State Calendar

For the 27 cool-season states, the single most important feed of the year is in September. For the 12 warm-season states it is late April, once soil temperature holds at 65°F. Find your state in the table below for the full calendar.

The soil temperature rule

Every extension service gives the same trigger. Warm-season grasses get their first feed when soil temperature at 4 inches deep sits at or above 65°F and the lawn has greened up. Cool-season grasses get their main feed in early autumn as night temperatures drop and the grass moves nutrients into its roots. A $10 soil thermometer beats any calendar, because spring arrives on a different date every year.

When to fertilize your lawn, by state

Transition zone states get two answers, because the right timing depends on whether you have a cool-season lawn like tall fescue or a warm-season lawn like bermuda or zoysia.

Cool-season lawns: September does most of the work

In the 27 cool-season states, if you only fertilize once a year, do it in September. The grass is recovering from summer stress and moving energy into its roots, so nitrogen applied then thickens the turf and builds the root system going into winter. Apply about 1 pound of nitrogen per 1,000 square feet. A second application in mid to late autumn is the next most valuable, and a light spring feed is optional.

Warm-season lawns: wait for green-up, stop by mid August

In the 12 warm-season states, the first feed goes down after the lawn has fully greened up, which is usually late April. Feeding too early pushes new shoots at the expense of roots and leaves the lawn exposed to a late frost. From there, feed every 6 to 8 weeks through the growing season, and stop by mid August. St. Augustine lawns should not be fertilized after mid September.

Transition zone lawns: your grass decides, not your state

The 12 transition zone states carry both kinds of lawn, so the state alone will not tell you when to feed. A tall fescue lawn in Kentucky runs on the cool-season calendar. A zoysia lawn on the same street runs on the warm-season one. Identify your grass first, then follow the matching column above.

How we built this calendar

Each state is assigned its USDA hardiness zone range and its turfgrass zone, then the standard extension-service feeding rules are applied to that zone. The month windows are bands derived from those rules, not measured dates, and they will shift by a week or two with the season. The soil temperature trigger is the accurate instruction. Sources: USDA Plant Hardiness Zone Map (2023 revision) and the turfgrass recommendations published by US land-grant university extension services, including Clemson HGIC, NC State Extension, UF/IFAS, Texas A&M AgriLife, Purdue Extension, University of Wisconsin Horticulture and University of Maryland Extension. Last updated 2026-08-19. You are welcome to cite or reproduce this table with a link back to this page.

Work out exactly how much product that is with the free lawn fertilizer calculator, check the best grass type for your state, or get a free personalised lawn care plan built around your grass and your climate.