Free Tool
Frost Date Calculator & Planting Calendar
Select your USDA hardiness zone to see your average frost dates and a personalized planting calendar for 32 vegetables and herbs. All timing data is cross-referenced from university extension sources and verified seed company guides.
Not sure? Look up your zone on the USDA map
Understanding Frost Dates
What are frost dates and why do they matter?
Your average last spring frost and first fall frost dates define the boundaries of your growing season. Nearly every planting decision in the vegetable garden is timed relative to these two dates. Cool-season crops like peas, spinach, and kale go in weeks before the last frost. Warm-season crops like tomatoes, peppers, and squash wait until after all frost danger has passed. Getting this timing right is one of the simplest ways to improve your garden's success rate.
Zone averages vs. your actual frost dates
The dates shown here are zone-band averages derived from NOAA climate normals. Your actual frost dates depend on elevation, proximity to water, urban heat island effects, and local terrain. Coastal properties often get an extra week or two in fall compared to inland areas at the same latitude. If you know your specific frost dates from local observation or a nearby NOAA weather station, use the custom override to get more precise planting windows.
Soil temperature matters as much as air temperature
Even after the last frost date passes, cold soil can stall germination or kill transplants. Warm-season crops need soil at 60-65F or above to establish properly. A cheap soil thermometer is one of the best investments a gardener can make. Measure at 4 inches deep, first thing in the morning, for the most accurate reading. Raised beds warm faster than in-ground plots, and black plastic mulch can raise soil temperature by 5-10 degrees.
Succession planting for continuous harvest
Fast-maturing crops like radishes, lettuce, and arugula benefit from succession planting -- sowing new rounds every 1-3 weeks instead of one large planting. This spreads your harvest over weeks or months instead of producing everything at once. The planting calendar above shows succession intervals for crops where this technique applies.
Common Questions
How do I find my average frost dates?
Your average frost dates are determined by your USDA hardiness zone and local climate station data. Select your zone in the calculator above for zone-band averages, or look up station-specific dates through NOAA Climate Normals or the Old Farmer's Almanac frost date tool by zip code.
What is the difference between last frost and first frost?
The last spring frost is the average date of the final freezing temperature (32F) in spring. The first fall frost is the average date of the first freeze in autumn. The days between define your frost-free growing season.
When should I start seeds indoors?
Indoor start times are counted backward from your last frost date. Warm-season crops like tomatoes and peppers need 6-10 weeks indoors. Cool-season crops like broccoli and lettuce need 4-8 weeks. The calculator shows exact windows for each crop.
What does frost tolerance mean?
Hardy crops survive hard frosts and can be planted well before the last frost date. Semi-hardy crops tolerate light frost but not sustained freezing. Tender crops are killed by any frost and must wait until all danger has passed.
Can I use this for fall planting?
Yes. The calendar shows fall planting windows for cool-season crops like garlic, kale, peas, carrots, and more. Fall windows are counted backward from your first fall frost date.
Where does this data come from?
Frost dates are based on NOAA 1991-2020 Climate Normals. Planting timing is cross-referenced from Johnny's Selected Seeds, Cornell Extension, UMass Extension, UMaine Extension, and the New England Vegetable Management Guide. Each crop was verified against at least two sources.
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Want a planting plan built for your specific yard?
This calculator gives you the general timing. A site consultation gives you the specifics -- which varieties perform best in your soil, how your microclimates affect planting dates, and a custom schedule built around your goals.
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