About when.garden
when.garden tells you when to plant — for any town on Earth. Enter a place and get its frost dates, growing-season length, climate zone, and per-crop sow, transplant and harvest windows — each shown with its source and a confidence score, so you know how far to trust it.
What you get
Last spring and first fall frost (50% and 10% probability) — the backbone of every planting date.
Frost-free days and your Köppen climate zone, so you see your window at a glance.
For ~30 crops: when to start indoors, transplant, direct-sow and harvest — keyed to your local frost.
Every figure says whether it's station-based or modeled, and scores how much to trust it (0–100).
How it works: four ways to know
Planting dates aren't a weather forecast — they're a climate baseline, so you look them up once, not every day. But “anywhere on Earth” isn't one method: a last-spring-frost date means nothing on the equator, and the tropics plant by rain, not cold. So when.garden uses whichever method fits a place — and every date tells you which one produced it.
Where winters freeze, we derive the last spring and first fall frost from 30-year climate normals (1991–2020), then key each crop off its frost tolerance and days-to-maturity.
Near the equator there's no frost to anchor to, so timing follows the rains — sow into the wet season, worked out from the local rainfall calendar.
Some countries publish official planting calendars (FAO's crop calendars, national agriculture bulletins). Where they exist, we use them directly — observed, not modeled.
Everywhere else, we match each crop's published temperature and rainfall needs (FAO ECOCROP) against a town's climate normals to model its window — the piece that makes “anywhere” literally true.
Whichever method a figure comes from, it's labelled — station, observed ormodeled — and carries a 0–100 confidence score; modeled values are never dressed up as measured. Today's live towns run on the frost method from curated normals; the tropical, observed-calendar and modelling layers are rolling out as coverage grows. The full derivation, including where it can be wrong, is on the Data & methodology page.
Where the data comes from
How to use it
- Search your town (or the closest one) in the box at the top.
- Read the anchor facts — last/first frost, frost-free days, and climate zone.
- Scan the crop calendar to see every crop's windows on one 12-month axis.
- Click a crop for step-by-step dates, the days-to-maturity, and the rule of thumb behind them.
What to expect
We headline the safe frost date — the ~90% date, past which frost is unlikely (about 1 year in 10) — because that's when it's safe to set out frost-tender crops. The typical (median) date is shown alongside, and cold-hardy crops (kale, peas, lettuce) can go earlier. Your own microclimate (a slope, a city, a coastline, a cold-air pocket) can still shift things a week or two — treat every date as a well-informed starting point, then watch your own sky.
- Every place shows whether its data is station-based or modeled, and its distance to the nearest station.
- A 0–100 confidence score reflects record length, station distance and year-to-year variance.
- Today's launch figures are curated from published normals; the automated station-by-station pipeline is rolling out (see methodology).
Coverage
Live today: Australia, New Zealand, the United Kingdom, Germany, France, Japan and Canada, with more countries rolling out. Because it draws on NOAA's ~132,000-station global network and NASA's worldwide grid, any town on Earth can be added — that's the point.