Pre-Emergent Guides by State
When to apply pre-emergent herbicide depends on where you live. Find your state below for local timing, recommended grass types, and expert resources.
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Warm-Season States
Apply pre-emergent early (Jan-Mar). Warm-season grasses dominate.
Alabama Extension dates by region Arizona Extension dates by region Arkansas Late February or early March California Extension dates by region Florida Extension dates by region Georgia Extension dates by region Hawaii No verified Extension date Louisiana Late January to early March, depending on region Mississippi Extension dates by region South Carolina About March 1 (coastal and central) to March 15–30 (Piedmont and mountains) Texas Extension dates by region
Cool-Season States
Apply pre-emergent later (Apr-May). Cool-season grasses dominate.
Alaska No verified Extension date Connecticut Between forsythia full bloom and lilac or flowering dogwood bloom Delaware 10 to 14 days before crabgrass germinates (usually March 15 to April 15) Illinois Early to mid-April in the south to late April–early May in the north Indiana No later than March 15–April 1 in the south to April 10–25 in the north Iowa Early to mid-April in the south to late April–early May in the north Maine Before forsythia blooms Maryland Mid-March on the Eastern Shore to early April in western Maryland Massachusetts Late April or early May Michigan No verified Extension date Minnesota Mid-April to mid-May Nebraska April 15 to the first week of May in eastern Nebraska New Hampshire Late April or early May, around forsythia full bloom New Jersey Before crabgrass germinates in April New York When soil reaches 55 to 59°F North Dakota Before soil averages 55°F Ohio Early April, before crabgrass germinates Pennsylvania March 15 to May 15, depending on region Rhode Island When forsythia blooms begin to fade South Dakota Extension dates by region Vermont Late April or early May (New England guidance) West Virginia No verified Extension date Wisconsin Early May, or earlier after a warm late April
Transition Zone States
Both warm and cool-season grasses grow. Timing varies by grass type.
Kansas Around April 15; April 1 in southeast and May 1 in northwest Kansas Kentucky No verified Extension date Missouri Late March to mid-April New Mexico No verified Extension date North Carolina Mid-February east of Raleigh to very early March in the western Piedmont Oklahoma By March 15 to April 1 Tennessee Late February or early March in West Tennessee, mid-March to early April in East Tennessee Virginia Early March in Hampton Roads
Dry / Western States
Dry climate with lower weed pressure. Timing varies by elevation.
Colorado Extension dates by region Idaho Before crabgrass germinates, mid-March to mid-April depending on region Montana Extension dates by region Nevada Mid-March to mid-May Oregon When soil reaches 50 to 55°F Utah Extension dates by region Washington When soil reaches 50 to 55°F in eastern Washington Wyoming After the last killing frost, as soil warms
Get Local Timing
State-level guides give you a general window, but timing at your location depends on local weather conditions. Use our GDD tracker with your ZIP code for a more local accurate recommendation.
Check Your ZIP Code