Find out if it's too late to seed your lawn based on your location and grass type. Get personalized seeding windows and expert recommendations.
How it works:
This calculator uses your ZIP code to determine your regional climate zone and frost dates, then calculates optimal seeding windows based on your specific grass type. Results are conservative to maximize your chances of successful establishment.
Receive timely reminders for optimal seeding windows and seasonal lawn care advice
Seasonal Guides
Perfect timing for your region
Expert Advice
From lawn care professionals
Cool-season grasses (like Kentucky Bluegrass and Fescues) thrive in fall seeding when soil is cooling but air is still warm, while warm-season grasses (like Bermuda and Zoysia) need to be seeded in late spring or early summer when soil temperatures reach 65-70°F.
You may still have success in the "acceptable" window, though establishment may be slower or require extra care like more frequent watering. Outside these windows, consider using sod for immediate results or wait for the next optimal seeding period.
Generally no. Even during warm winter periods, the short daylight hours and unpredictable weather patterns make successful establishment unlikely. Seeds may germinate but struggle to establish strong root systems before summer stress.
Optimal windows provide the best conditions for rapid germination and establishment. Acceptable windows work but may require more care, take longer to establish, or have slightly lower success rates. Both are better than seeding outside these periods.
Soil temperature is key! For cool-season grasses, soil should be 50-65°F. For warm-season grasses, aim for 65-70°F. You can use a soil thermometer or check with your local extension office for current soil temperatures in your area.
For cool-season grasses, seed 6-8 weeks before the first expected frost to allow establishment. For warm-season grasses, wait until after the last frost when soil temperatures are consistently warm. Our calculator accounts for these frost dates.
If your ZIP code isn't found, you can select "Other/Not Listed" for general guidance, or use a nearby ZIP code from the same climate region. Consider contacting your local extension office for region-specific advice.
Yes! Overseeding can be done in the "acceptable" windows when you want to thicken existing grass. The timing is similar to new seeding, but you may need to prepare the existing lawn first by dethatching or aerating.
Our calculations are based on USDA frost date data and established horticultural best practices. However, local microclimates, elevation, and weather variations can affect actual conditions. Always monitor local weather forecasts and soil temperatures.
If you have a mixed lawn, use the timing for the predominant grass type, or select "Other/Not Listed" for general cool-season guidance. For best results, consider taking our grass identification quiz to determine your primary grass type.
Yes! Our recommendations are guidelines based on historical averages. If you're experiencing unusual weather (drought, excessive rain, early/late frosts), adjust accordingly. Always check soil moisture and temperature before seeding.
Avoid seeding during active drought conditions. Seeds need consistent moisture to germinate and establish. If you're in a drought, wait for adequate rainfall or ensure you can provide consistent irrigation. Consider the next seeding window instead.
