When to Apply Pre-Emergent in Colorado
The best time to apply pre-emergent in Colorado is mid-april to early may. Use the GDD tracker below for precise timing based on your ZIP code.
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Pre-Emergent Timing in Colorado
Spring Application
Mid-April to early May
Target: when soil temperature reaches 55°F at 4-inch depth for several consecutive days
Common Grass Types in Colorado
Colorado has a dry, western climate with lower humidity and less natural rainfall. While crabgrass pressure may be lower than in humid regions, irrigated lawns still benefit from pre-emergent applications timed to local soil temperatures.
Pre-Emergent Tips for Colorado
- Along the Front Range (Denver, Colorado Springs), apply in mid to late April.
- Mountain communities at higher elevations may not need pre-emergent until May or June.
- Colorado's dry climate means crabgrass pressure is often lower than in humid states.
- Buffalo grass and blue grama lawns may need less weed control than bluegrass.
- Water in the pre-emergent within 48 hours, as dry conditions can reduce effectiveness.
Local Expert Resources
For research-backed lawn care advice specific to Colorado, visit your state's university extension service:
Colorado State University ExtensionFrequently Asked Questions
When should I apply pre-emergent in Colorado?
In Colorado, the best time to apply pre-emergent is mid-april to early may. Use Growing Degree Days (GDD) tracking for precise timing based on your local soil temperature.
What grass types are common in Colorado?
Common grass types in Colorado include Kentucky Bluegrass, Tall Fescue, Buffalo Grass, Blue Grama Grass. Colorado is in USDA Hardiness Zones 3b-7a.
What is the best pre-emergent herbicide for Colorado?
For most lawns in Colorado, 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 Colorado?
Apply pre-emergent when soil temperature at 4-inch depth reaches 55°F for several consecutive days. In Colorado, this typically corresponds to 150–200 Growing Degree Days (base 50°F) accumulated from January 1.
Track Your GDD
Don't guess -- use Growing Degree Days to know exactly when to apply pre-emergent herbicide at your location.
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