Why the British growing calendar still matters

Walk around any UK food festival and you will see plenty of stalls selling much the same thing, whatever the month. The ones worth queueing for are different: they change what they offer because their produce comes out of the ground a few miles away, and it ripens when it ripens.

Britain's seasons are short and sharp. English asparagus runs for around eight weeks. Outdoor strawberries peak for a month or so. Grouse is available from 12 August, pheasant from 1 October. Knowing the calendar tells you what to look for, what to queue for, and what to walk past without regret.

Spring: asparagus, wild garlic and the first greens

Asparagus is the great event of the British food year. The traditional season runs from St George's Day, 23 April, to midsummer, 21 June, though a mild spring can bring the first spears forward by a week or two. Choose stalks with tight, compact tips and a faint purple flush near the bud. Good spears squeak faintly when rubbed together and snap cleanly rather than bending. If you buy at a festival, ask when they were cut — the answer should be "this morning" or "yesterday".

• Wild garlic: April and May, sold as leaves, pesto, butter or soup. The white star flowers are edible too.
• Forced rhubarb: January to March, grown in darkened Yorkshire sheds. Slender pink stems, far more delicate than the outdoor crop that follows.
• Purple sprouting broccoli: February to April, sweet and nutty, best simply steamed with butter.
• New potatoes: Cornish earlies from April, Jersey Royals into July. Rub the skin off with your thumb rather than peeling.

Summer: strawberries, peas and sweetcorn

British strawberry season is short and worth waiting for. Outdoor crops start in June and run to September, but the flavour peaks in a narrow window in late June and July. The best fruit is rarely the biggest: small, deeply red berries smell sweet before you bite. Many growers bring a cheaper "jam" grade to festivals — slightly soft, perfect for eating on the spot.

Peas and broad beans arrive at the same time. Pods should feel heavy and full; older ones go starchy within a day or two of picking. Sweetcorn follows from July to September and is a different vegetable entirely from the supermarket version — the sugar turns to starch within hours, so buy cobs with tight green husks and cook them that evening.

Tomatoes run from July through October, with heritage varieties in every colour at larger festivals. Kentish cherries appear in June and July, and plums and apricots follow in August.

Autumn: apples, game and mushrooms

September is when the British larder fills up. Apple season begins with Discovery in late August and moves through Cox, Egremont Russet and Bramley; many festivals hold an apple day in October where you can taste a dozen varieties side by side and buy bags of seconds for cooking. Pears, quince and cobnuts arrive alongside them.

Game is the other autumn headline. Grouse comes into season on 12 August, partridge from 1 September, pheasant from 1 October. A good stall will tell you where the birds were shot and how long they have been hung. If you have never cooked pheasant, start with the breasts: brown them quickly and keep them pink.

• Wild mushrooms: September to November. Buy from a stall that names its forager, and never pick your own without expert guidance.
• Native oysters: back on the menu from September, once the months contain an "R".
• Squash and pumpkins: October, roasted with sage and brown butter.

Winter: brassicas, roots and forced rhubarb

By December the choice narrows, but it does not become dull. Kale, leeks, sprouts and purple sprouting broccoli are at their best after a frost, which converts some of their starch to sugar. Parsnips and carrots taste noticeably sweeter for the same reason, so look for roots a grower has lifted in cold weather rather than pulled from a cold store.

Winter markets are also the moment for smoked fish, cured meats and preserves made with the last of the autumn fruit, plus the first forced rhubarb from Yorkshire in January. Celeriac, swede and Jerusalem artichokes make soups that will carry you through to spring.

How to shop a seasonal stall

A few habits will serve you well at any festival.

• Ask what is best today. Stallholders sell what is at its peak and will steer you right.
• Buy less, more often. Seasonal produce is at its best within a day or two of picking.
• Check the label. "Produced in the UK" is not the same as grown here.
• Carry cash and a cool bag. Many small growers still prefer it, and a cool bag keeps strawberries and asparagus happy on the journey home.

Eat with the calendar and the rewards are obvious: asparagus in May tastes of the thing itself, not of a plastic tray. That is worth planning a weekend around.