Ah, the great British caravan. It does earn its keep. Think of how, each July, thousands of campers set off in motorhomes and vans to follow that illustrious bicycle race, the Tour de France. But back in 1976, the gardener Joy Larkcom and her family were setting off on a rather different adventure: a Tour de Vegetables.
Today, Larkcom is one of Britain's most highly rated horticultural writers, but her books are all rooted back in that year-long European Good Life cruise, in search of traditional vegetable-growing techniques and heritage-seed varieties.
By her mid-twenties, Larkcom was already a globetrotter – she'd taught in Thailand, been a librarian in Canada and come back to England to work in newspapers – so she was well prepared by the time they packed up the second-hand caravan and vintage towing van. It's a gloriously home-grown picture she conjures up: "We took bikes for short journeys, a tent for emergencies, tins of English humbugs for presents, spares for the van, cookery books, dictionaries, maps, reference books, biscuit tins with silica gel bags in them for seed storage. We even took a telescope."
Once the caravan made it across the Channel, the family were taught how to make a delicious mushroom sauce by a French railwayman and learnt to cook wild chicory from Italians. From the hedge of a Bologna campsite they were served edible poppies, thistles and wild asparagus. They picked wild thyme and marjoram in Provence, and were wowed by the couve-galega, a striking Portuguese cabbage that can reach 8ft in height. They even made it to Yugoslavia, where they saw nurseries heated by hot springs, and Hungary, where they admired the state-run seedbank. Following this good example, Larkcom collected seeds wherever they went, and sent them back to the UK Vegetable Gene Bank in the process of being established in Warwickshire.
So what did her vegetable odyssey teach Joy Larkcom? Well first, there were those veg that Britons considered "weird" but which were grown daily on the Continent. In Belgium alone, the summer selection included purslane, chervil, corn salad, sorrel and herb patience; and in winter, she found celeriac, scorzonera, kohlrabi and chicory – things we've now heard of, but have mostly never actually cooked. Odd Portuguese pumpkins and broad beans, unusual Hungarian peas, stone-pine kernels, lupin seeds – she collected them all, and often some recommendations for accompanying alcoholic drinks, too.
That's the second important part of her legacy: Larkcom has always been interested in recording the way vegetables are cooked and served. She has made a huge contribution to our knowledge about how to make things tasty, and for that we have to thank her. (Not to mention all those farmers, smallholders, allotment growers and market gardeners across Europe who fed her, then gave her the recipe.)
Finally, she collected techniques for growing. She observed rootstocks, raised beds, measured path widths and plant spacing, examined insect traps. She single-handedly brought back the idea of "cut and come again", where you sow a crop of salad from which individual leaves can be picked over the course of a few weeks, and championed "intercropping", where a fast-growing crop fills gaps before a slow-growing one matures. And she campaigned passionately to stop British vegetable growers from sowing in rows, changing over to a more intensive, small-block system that would allow less moisture to leave and more worms to flourish.
And perhaps Joy Larkcom did also bring back one more thing from her tour. Like Elizabeth David, she made the 1970s a decade of discovery. We turned our eyes to Europe and found a new world to discover, a different way of doing things that was full of exotic charm and real value. This is not a tangible, financially straitened Europe, but a delicious, seductive vision. All thanks to that caravan.
Larkcom's memoirs, 'Just Vegetating', are out now (Frances Lincoln, £18.99)