Oklahoma Lawn Care Calendar — 2026

January is a full-dormancy month for Oklahoma lawns. Cool-season grasses like bermuda, buffalo, tall-fescue have stopped active growth and are protected by snow cover or mulched leaves. Avoid foot traffic on frozen or frosted grass — the blades are brittle and will leave footprints that stay visible into spring.

February in Oklahoma is a dual-signal month. Warm-season pockets in the south of the state may begin transitioning, but most of the state is still firmly dormant. Use this month to plan your calendar, service equipment, and order pre-emergent based on your county.

March is when the Oklahoma lawn-care calendar truly begins. Pre-emergent herbicide should be applied during the window of early to mid-March for Bermuda; forsythia bloom (mid-April) for cool-season KC-area lawns. Missing this window is the single most expensive mistake homeowners make — the crabgrass, goosegrass, and annual bluegrass seed bank in Oklahoma soils will germinate the moment soil temperatures cross 55°F for three consecutive days, and once those weeds are up you cannot stop them with pre-emergent this season.

Spring timing in Oklahoma can vary by 3 to 6 weeks from the north of the state to the south — use your local soil temperature reading rather than a calendar date to trigger pre-emergent and first fertilizer applications.

April brings Oklahoma lawns into active growth. Warm-season lawns complete their green-up and are ready for the first fertilizer application April once Bermuda is fully greened up. Cool-season pockets in the north of the state should wait until May. Never fertilize grass that has not fully greened up — you will feed weeds and stress the turf. Last-frost dates across Oklahoma: April 10 (north), March 25 (OKC), March 15 (south).

Spring timing in Oklahoma can vary by 3 to 6 weeks from the north of the state to the south — use your local soil temperature reading rather than a calendar date to trigger pre-emergent and first fertilizer applications.

June is peak growing season in Oklahoma. Lawns are at maximum density and should be mowed weekly — or every 5 to 7 days for fast-growing Bermuda. Water deeply once or twice per week to encourage deep roots rather than shallow daily sprinklings. Aim for 1 to 1.5 inches of water total per week, including rainfall. If you see ruts from the mower, the soil is too wet to be mowing on.

Oklahoma watering guidance: irrigate deeply and infrequently (1 to 1.5 inches per week total, including rainfall) rather than lightly and daily. Deep watering drives roots down; shallow watering keeps them at the surface where they dry out in the first heat wave.

July stresses Fescue and cool-season components in Oklahoma while warm-season lawns thrive. Raise mower heights on Fescue to 4 inches, let the grass go semi-dormant if drought hits, and save fertilizer for September. Bermuda and Zoysia continue weekly mowing at 1.5 inches and can receive a mid-season fertilizer boost if color is fading.

August in Oklahoma is planning month for Fescue overseed and a continued growing month for Bermuda. Order Fescue seed, rent a core aerator for September, and plan the same-day aerate-and-overseed program that produces the best results in transition zones.

September is the critical Fescue month in Oklahoma. Aerate and overseed September for NE Oklahoma Fescue. This is the only window that produces lasting density in the transition zone — spring overseeding almost always fails because Fescue seedlings cannot survive their first summer. If you only do one lawn-care task per year and you have Fescue, make it September overseeding.

Sharpen your mower blade before the final mows. A dull blade shreds rather than cuts, leaving fringed tips that brown out and give disease a foothold over winter. Clean cuts heal quickly even in cooling weather.

October is winterizer month across Oklahoma. Apply the winterizer fertilizer in October — a fertilizer with higher potassium than nitrogen — to build cold tolerance in the grass crown. Cool-season components are still growing; warm-season components are entering dormancy. Mow at cool-season heights (3 inches) and remove leaves weekly.

If you have not done a soil test in three years, October is a good month to pull samples and submit them to your state Extension Service. Results come back in 2 to 3 weeks and will tell you exactly what to apply next spring.

November is the end of the active lawn-care season in Oklahoma. Do your final mow at 2 inches. Drain the irrigation system. Remove all leaves before winter sets in.

December is a fully dormant month in Oklahoma. No mowing, no fertilizing, no watering. Clean and store your mower for winter. Dormant grass is easily damaged by foot traffic on frozen mornings — keep off the lawn when frost is visible on the blades.