Free planting calendar
When should I sow? Ask the SowClock.
Tell us your town (or your frost dates) and get a personal calendar for 30 vegetables and herbs: when to sow indoors, plant out, sow outdoors and start harvesting.
- Free, no sign-up
- Timings from university extension services
- Northern and southern hemispheres
Last updated · Sources checked on
What the sources say
Planting times are usually counted from the average date of the last spring frost. Hardy crops such as peas, lettuce, spinach and radish can go in as early as 2 to 4 weeks before it; tender crops such as beans, sweet corn and cucumbers around that date; very tender crops such as tomatoes, peppers and squash typically 2 weeks or more after it.
(source: CSU Extension)Where do you garden?
North positive, south negative. Not needed for the calendar.
Your frost dates
Filled in from your town; you can change them. Not sure? See how to find your last frost date.
Everything is computed in your browser. Nothing you type is sent to us or stored.
Your planting calendar
Choose your town, or type your two frost dates, and your calendar sprouts here.
Sow indoors Plant out Sow outdoors First harvest Last frost First frost
Rain and temperature
Daylight
Moon phases this month
Gardening tradition, not science
Sowing by the moon is an old and widespread tradition, and many gardeners enjoy following it. Scientific evidence that moon phases affect plant growth is lacking: a review of more than 120 references found no consistent lunar effect on plants. We show the phases for those who like to use them; the calendar above does not depend on them. (source: Illinois Extension)
Phases computed in your browser with standard astronomical formulas (Meeus) and checked against U.S. Naval Observatory tables.
Good to know: the limits
- Frost dates are averages of 1991-2020 weather at a nearby station, not a forecast. A frost can come later in any year: watch your local forecast and keep fleece handy.
- Timings are general rules from US university extension services, given in weeks from the last frost. In maritime climates such as the UK, the RHS advises waiting until nights are consistently above 7 °C before planting out tender plants, which can be later. (source: RHS)
- Days to harvest vary a lot with variety and weather: the harvest dates are rough.
- In frost-free or very hot climates, frost-based calendars fit poorly.
Frequently asked questions
What is a last frost date?
It is the average date of the last spring night when the air temperature falls to 0 °C (32 °F) or below. "Average" here means that in about half of years the last frost comes later. Many sowing and planting rules from university extension services are given in weeks before or after this date.
Where do the town frost dates come from?
From daily minimum temperatures measured at weather stations from 1991 to 2020 (NOAA's Global Historical Climatology Network, daily), matched to the nearest suitable station within 40 km. The method, coverage and limits are explained in our guide on how SowClock finds your frost dates.
My town is not listed. What can I do?
Pick a nearby larger town at a similar height, or choose "Another country" and type your own frost dates. Our guide on how to find your last frost date lists official sources by country.
Does it work in the southern hemisphere?
Yes. If your last spring frost is in September or October and the first autumn frost in April or May, the calendar runs from one year into the next.
Is what I type sent anywhere?
No. The calendar is computed in your browser. Choosing a country downloads that country's town list from this site; your town, dates and choices are never sent to us and are not saved. To work offline, your browser keeps a copy of the pages and town lists you have opened in its own cache, on your device.
Guides
How to find your last frost date
Official places to look up average frost dates in the US, Canada, the UK, Ireland, Australia, New Zealand and elsewhere.
What a frost date really means
An average frost date is a 50/50 bet, not a promise. How to read it, and how to play it safer.
Sowing indoors vs sowing direct
Which crops to start on a windowsill, which to sow straight in the ground, and why.
How SowClock finds your frost dates
Our data, method, coverage, checks against official normals, and the limits you should know.
Sources
- Colorado State University Extension: Vegetable Planting Guide (CMG GardenNotes #720, reviewed September 2024)
- University of New Hampshire Extension: Growing Vegetables, When to Plant Your Vegetable Garden (fact sheet)
- Alabama Cooperative Extension System: Vegetable Seasons in Alabama (ANR-1165, reviewed January 2025)
- Oklahoma State University Extension: Cole Crop Production (Broccoli, Cabbage, and Cauliflower)
- University of Illinois Extension: Herbs, Basil
- University of Illinois Extension: Herbs, Cilantro/Coriander
- University of Illinois Extension: Herbs, Dill
- University of Illinois Extension: Herbs, Parsley
- Purdue University Extension: Growing Herbs (HO-28)
- Utah State University Extension: Suggested Vegetable Planting Dates, Grand and San Juan Counties (2024)
- NC State Extension: Bulb Onions
- RHS: When to plant out tender plants, avoiding late frosts
- NOAA NCEI: Global Historical Climatology Network daily (GHCNd)
- GeoNames: free geographical database (cities with a population over 15,000), CC BY 4.0
- University of Illinois Extension: Lunar Influence on Gardening (The Garden Scoop, April 2022)
- U.S. Naval Observatory, Astronomical Applications: Data services
- NOAA Global Monitoring Laboratory: Solar Calculator
Sources checked on 1 November 2026.