Buy it now or wait a year: shopping the last fortnight of September

The last fortnight of September is the changeover. Two lists are running at once on every good stall: things in their final days, which you either buy now or wait the best part of a year for, and things just arriving, which will be there all autumn and need no hurry at all. Knowing which is which is most of the skill of seasonal shopping.

Buy now — these are nearly gone

Outdoor tomatoes. The ones ripened in real sunshine rather than a heated glasshouse are finishing. Buy a tray of the misshapen cheap ones and cook them down into sauce for the freezer; it is the single most worthwhile hour of the month. Keep them out of the fridge — cold flattens both texture and flavour.

Sweetcorn. Its last good weeks. Sweetcorn starts turning its sugars to starch the moment it is picked, which is why a cob from a stall a few miles away tastes nothing like one that has crossed a continent. Look for a plump, fresh-cut stem and tightly wrapped husks, and cook it the day you buy it.

Runner and French beans. Choose pods that snap cleanly rather than bend. If there are more than you can eat, slice, blanch for two minutes in boiling water, cool in cold water and freeze — they hold up far better than most people expect.

Damsons, greengages and the last plums. Damsons in particular have a season of barely a month. They freeze whole, stones and all, and the stones are easier to deal with after cooking anyway.

Blackberries. Best early in the month and going over quickly now. Pick or buy them dry, freeze them spread on a tray first, then bag them so they don’t set into a single block.

No rush — these are only starting

Squashes and pumpkins. They will be around for months and improve with a little age. Look for a hard skin you can’t dent with a thumbnail and a dry, corky stalk still attached — a missing stalk is where rot gets in. Kept somewhere cool and dry, not the fridge, a good squash lasts until the new year.

Main-crop potatoes. The lifting is happening now and they are cheap by the sack. Store them in paper or hessian, never plastic, somewhere dark and airy; light turns them green, and green patches are bitter and best cut away.

Apples and pears. The eaters are at their peak, but the keepers — Bramleys, russets — are the ones worth buying in quantity. Store them cool and dark, not touching each other, and check them over every few weeks. Pears are the exception: buy them slightly under-ripe and finish them in the fruit bowl.

Leeks, kale, beetroot and the first parsnips. All improving from here. Parsnips are genuinely sweeter after a frost, so there is no advantage in rushing.

How to shop the fortnight

Shop little and often at this time of year, because the stall changes weekly. A producer box does the choosing for you and tends to be heavy and good value while the last gluts overlap the first storers — see what growers near you are packing on the boxes page. To find the people doing the growing, the directory at /directory lists producers by what they make and where they are. And if you want the whole picture rather than one fortnight of it, the month-by-month view lives on our seasonal produce calendar at /resources/uk-seasonal-produce-calendar.