Guides
Short, friendly and sourced: everything behind your planting calendar.
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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.
A friendly guide, not a guarantee. Frost dates are averages of past weather, not forecasts: a frost can come later than the average in any year. Crop timings are general rules from university extension services; your soil, microclimate, variety and the weather on the day matter too. Check your local forecast before planting out tender plants.