When to Apply Pre-Emergent in Alabama

The spring window in Alabama varies by area; see the published dates below, and the fall window begins once estimated 2-inch soil temperature cools to about 70°F and stays there for several days, typically late September to October. Use the GDD tracker below for precise timing based on your ZIP code.

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Enter your ZIP code for precise Growing Degree Day data based on your nearest weather station.

Spring Pre-Emergent Timing in Alabama

Spring Application

  • South Alabama: February
  • Elsewhere in Alabama: no published date

Alabama Extension’s South Alabama lawn calendar lists February for preemergent herbicide. We have not found a dated Alabama Extension window for the rest of the state.

Source: Alabama Extension: South Alabama Gardening: St. Augustine, Zoysia & Bermuda Maintenance

Missed the window? A pre-emergent will not kill crabgrass that has already come up. See what still works when it’s too late.

Fall Pre-Emergent Timing in Alabama

Watch estimated 2-inch soil temperature cool to about 70°F and stay there for several days. As its own display heuristic, the tracker shows Getting Close above 70°F through 75°F only while the estimate is cooling, and Too Warm above 75°F. It shows Apply Now once the estimate has been at or below 70°F on each of the last four data days and is still above 55°F, and Window Passed at or below 55°F. UGA Extension advises applying before soil cools to 55°F, when winter weeds begin germinating.

Fall Application

Typically late September to October

Targets Poa annua, henbit, and chickweed before germination.

Product Choice

Prodiamine or dithiopyr

Clemson rates both for good-to-excellent annual bluegrass control. Once the window is passed, the tracker shows no pre-emergent product because it offers little benefit after annual bluegrass is established. Overseeding swaps these products for seeding-compatible mesotrione.

Common Grass Types in Alabama

Alabama has a warm-season climate, meaning soil temperatures rise early in the year. Crabgrass and other summer annual weeds can begin germinating as early as late winter, so early pre-emergent application is critical.

Warm-Season Climate USDA Zones 7b-9a
Bermuda Grass Warm-Season
Zoysia Grass Warm-Season
Centipede Grass Warm-Season
St. Augustine Grass Warm-Season

Local Expert Resources

For research-backed lawn care advice specific to Alabama, visit your state's university extension service:

Alabama Cooperative Extension System

Frequently Asked Questions

When should I apply pre-emergent in Alabama?

Published Extension timing for Alabama: South Alabama, February. Alabama Extension’s South Alabama lawn calendar lists February for preemergent herbicide. We have not found a dated Alabama Extension window for the rest of the state. Enter your ZIP to compare today with it.

What grass types are common in Alabama?

Common grass types in Alabama include Bermuda Grass, Zoysia Grass, Centipede Grass, St. Augustine Grass. Alabama is in USDA Hardiness Zones 7b-9a.

What is the best pre-emergent herbicide for Alabama?

For most lawns in Alabama, Prodiamine (Prodiamine 65 WDG) provides the longest-lasting barrier at 8+ months. If you are applying late, Dithiopyr (Dimension 2EW) is a better choice because it offers early post-emergent control on young crabgrass. Compare all pre-emergent options.

What soil temperature triggers pre-emergent application in Alabama?

Apply pre-emergent when soil temperature at 4-inch depth reaches 55°F for several consecutive days. In Alabama, ZIP results follow the published Extension timing instead of a GDD range.

Should I apply pre-emergent in the fall in Alabama?

Yes. In Alabama, watch for estimated 2-inch soil temperature to cool to about 70°F and stay there for several days; the calendar guide from our regional fall window table is typically late September to October.

More Alabama Timing Tools

Pre-emergent isn't the only lawn job worth timing by soil conditions. These trackers use the same Alabama weather station data.

Track Your GDD

Don't guess -- use Growing Degree Days to see where your location sits in the pre-emergent window.

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