Menus often boast of “heritage” fruits and vegetables – but what does that actually mean?

I shall let you into one of horticulture’s best-kept secrets. Heritage does not mean “a national treasure”.

Those of you old enough to remember the experience of visiting a restaurant will recall the pleasure of browsing a menu and choosing the vegetables or salad to accompany your main course, or the fruit for your pudding. And how we were seduced by the menu language. It was not just the strange brand of French that never properly matched what we were taught at school, but the English, too, where the keyword was “heritage”.

The word also crops up in seed catalogues and on the trays of plants you can find at (the now thankfully reopened) garden centres. It smacks of something truly special, equivalent to English Heritage and its guardianship of national treasures.

But I shall let you into one of horticulture’s best kept secrets. Attached to the names of vegetables and fruit, heritage does not mean “a national treasure”; it just means “old”. And thereby hangs one of horticulture and the restaurant trade’s biggest bluffs – because far from identifying a time-honoured speciality that has stood the test of years of gardening and culinary scrutiny, “old” too often simply means something peculiar in shape or colour.

Take the old purple-skinned potatoes that have become de rigueur in every vegetable catalogue. Or rather, don’t take them – because they are often prone to scab disease and in my experience have an inferior flavour to the best of modern kinds. And, like purple-podded French beans, they lose most of their colour when cooked, so even the appeal of an attractive appearance is lost.

Taste has far less to do with the age of the variety and much more to do with the age of the individual plant when it is picked or dug from the ground. Because as soon as a vegetable or fruit is harvested, chemical changes take place within its tissues that begin to alter the flavour, almost always in a way we find detrimental.

Many modern vegetable varieties, bred for the commercial market, are selected first for an ability to be harvested mechanically and a robustness to withstand the rigours of transportation. They will also have been selected for the pest and disease resistance so often absent from ancient types. But none of this means they are bereft of flavour and if the time between harvesting and eating is kept short, that flavour should be retained. However, that said, even the modern commercial “cold chain” (in which delicate crops like lettuce are chilled as they are picked from the field and remain chilled until they reach the supermarket shelf) still cannot produce a lettuce with the taste of one cut ten minutes ago from my own garden.

If you are also fortunate enough to have access to a garden at present, there is no better moment to borrow from another time of national crisis and emulate the Second World War “Dig for Victory” campaign and grow your own. There is still plenty of time to sow or plant vegetables for this season, but rather than being beguiled by the heritage tag so beloved of chefs, choose those that have an Award of Garden Merit from the Royal Horticultural Society – which means they have passed the test of reliability in modern garden conditions for yield, disease and pest resistance and, yes, of course, flavour.

Certainly, old varieties should be conserved in gene banks and other collections because of their possible value in future breeding programmes, but museum gardening as such never served any useful horticultural or culinary purpose.

Next week: Nina Caplan on drink