First came the orchards, established in the Clyde Valley by monasteries as far back as the fifth century. Commercial fruit production was big business from the 1600s, and a hundred years later, the valley could claim an estimated 75 per cent of Lanarkshire’s horticultural land.

By the 1920s the focus was on strawberries, until disease decimated the plants. In response, fields of glass were built: new water-heating technology provided the optimum temperature for growing tomatoes (16°C), and soon the area supplied the whole of Scotland, even occasionally exporting
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But a new plague hit this brave new industry in the 1970s: the fuel crisis. Acres of the 1930s greenhouses were collapsing and growers couldn’t afford to heat or rebuild them. When the Common Market import tariffs protecting growers were removed, competing with the continent became impossible. By 2009 only four growers remained, the largest being Jim Craig of Briarneuk Nursery, three miles south of Carluke. When he moved towards retirement in 2012, it seemed that the era of commercial cultivation of Scottish tomatoes was almost over.

‘I don’t see any youngsters wanting to take up the reins,’ Craig told The Larder in 2009. ‘We will be the last of the line, unless something major happens to change the marketplace.’

Just three years later attitudes to localism had changed dramatically enough to convince backers – including South Lanarkshire Council – to invest large sums of money in two newcomers in their early thirties with no tomato-growing experience. Scotherbs of Tayside also believed in the venture enough to give them an interest-free loan, and Jim Craig found himself advising the Clyde Valley’s next generation of growers.

Briarneuk Nursery is now home to Clyde Valley Tomatoes, and to David Craig (no relation) and Scott Robertson. They met Jim in April 2012 and, having sold their house to move into a caravan on site, by May the following year were picking their first cherry tomatoes.

After a winter spent clearing, weeding, cleaning and re-stocking, the glasshouses glint in the sun overlooking the valley, birdsong the only sound. Tomato growing is quiet, but not, as Craig and Robertson have found out, relaxing. As of August 2013, they have had just Christmas Day off from their ten thousand vines.

‘In many ways it’s like having children,’ says Craig. ‘Plants never take a day off; they need constant care – the right temperature, the right humidity, the fruit picking, and then it’s off to farmers’ markets.’

It might not be too long before they can take on the staff that will allow them more time off, as business has expanded rapidly. ‘In some ways we have been victims of our own success,’ says Craig of the huge interest in Clyde Valley Tomatoes. ‘Demand for the specialist tomatoes is outstripping supply. In the first few months we had ten enquiries a day – some people became quite aggressive because we couldn’t supply them.’

The restaurants that have been granted access to these tomatoes announce their provenance on menus with pride: the heritage of the fruit is a key part of its appeal.

‘We were so disappointed two years ago when we received the last delivery from Jim Craig,’ says Carina Contini, owner of the Scottish Café and Centotre in Edinburgh. ‘So to hear that a new generation were keen to start growing was fabulous news. We feel Clyde Valley’s tomatoes are the best in Britain.’

The success of the heritage and specialist tomatoes – they’ve planted fourteen varieties, and three of cucumbers – has convinced Craig and Robertson that this is the future of the business, and they intend to scale back the classic rounds. They would also like to launch their own range of chutneys to use up excess produce and to provide an income throughout the winter.

‘If there’s ever going to be a Scottish tomato revival,’ said Jim Craig in 2009, ‘I doubt I’ll be here to see it.’ Four years later, his glasshouses are stocked from end to end and the Clyde Valley’s tomatoes are red-hot news once again.