An availability window is the span of weeks during which a crop is typically harvested in a given area. Provinces publish these as guides: Foodland Ontario lists the months Ontario fruits and vegetables are normally available, and the British Columbia Association of Farmers' Markets keeps a month-by-month overview for its regions. Both carry the same caution — dates move with weather, region, and the specific variety.
A guide is a baseline, not a calendar lock
Treat the published window as the centre of a range. A late spring can push asparagus or strawberries back by a week or two; a warm autumn can stretch the tail of a tomato season. The provincial guides themselves say availability dates may change by several weeks depending on weather, region, or variety.
Why some local produce shows up out of season
Cold storage is the usual explanation. Apples, beets, carrots, onions, potatoes, and winter squash hold well and can be sold by the grower long after the field season ends. So a "local" apple in late winter is plausible from storage, while a "local" field tomato in that same month generally is not.
A quick test at the stall: ask whether an item is from this season's harvest or from storage. The answer tells you more than the window alone.
A simplified reading of common windows
The table below sketches typical harvest timing for southern parts of central Canada. It is a general reading of public provincial guides, not a guarantee for any single market.
| Crop | Typical field window | Storage extends to |
|---|---|---|
| Asparagus | Late spring | Fresh only |
| Strawberries | Early summer | Fresh only |
| Sweet corn | Mid to late summer | Fresh only |
| Field tomatoes | Late summer to early autumn | Fresh only |
| Apples | Late summer to autumn | Through winter |
| Carrots and beets | Summer to autumn | Through winter |
| Winter squash | Autumn | Into winter |
Adjusting for your region
Canada spans many growing zones, so a window for the lower mainland of British Columbia or southern Ontario will not match the Prairies or the North. The reliable move is to open your own province's guide and then confirm at the market, where the manager and growers know the current state of the harvest.