Last year saw the rise of purple vegetables from cauliflower to Brussel’s sprouts but next year we’ll see everything from black radishes, black corn and darling of health bloggers and Instragrammers, kale, taking a darker turn, according to the market’s annual Fruit and Vegetable Trends Report 2018.

Black produce, including a South American sweetcorn variety; aged garlic with umami flavour; radishes and Shetland Black Potatoes all received a name check as traders reflected on how dark hued produce has seen growth in demand from some of the capital’s most revered restauranteurs, providing a sneak peak at what the likes of Le Gavroche, The Dorchester, The Four Seasons and The Wolseley might choose to serve up next year.

The trend for black produce is predicted to continue into the new year alongside a renewed penchant for heritage. Market wholesalers reported seeing a distinct increase in the popularity of full-flavoured and quirky looking old-fashioned varieties such as sprouting and baby cauliflower; candy-striped beetroot; purple and yellow heritage carrots; short season Fenland celery and Red William pears – all traditionally used in times gone by. Similarly, innovative varieties that harp back to heritage produce, such as Chantenay carrots and piccolo parsnips, are also tipped for popularity.

Respondents also cited which new products that they had seen emerge in the last 12 months, with the top answer being unusual citrus. Giant citrus such as the Cedro lemons whose pith, zest and flesh can be fully utilised in cooking, made the list, including a variety known as limone di Ponza from the unspoilt island of Ponza; Asian citrus like Miyagawa clementines that have green skin, but orange fruit and the aromatic yuzu; Tangelo, which has a taste across between a tangerine and a grapefruit; and Bergamot – a fragrant fruit commonly used in cocktails.

Meanwhile, the produce which saw the biggest uplift in sales in 2017 was kale of all varieties; followed by berries particularly UK grown berries – golden raspberries, snow white strawberries, green strawberries and pink blueberries ; sweet potatoes and other specialist potato variants; and Datterini/San Marzano tomatoes. Driven by consumer trends, the elevated sales of these products are expected to carry into 2018, aided by an increased consumer leaning towards veganism, superfoods and British provenance. Wholesalers also reported an increase in the demand for ‘wonky’ or otherwise imperfect fruit and vegetables as consumers continue to toe the line from a sustainability and ‘war on food waste’ point of view.

The rise of more interesting salad ingredients, such as baby kale, tatsoi, winter purslane and land cress, has meant that Iceberg lettuce has suffered a sales decline and is unlikely to make a comeback in 2018.

Helen Evans, business development director for New Covent Garden Market, said: “It is interesting to reveal this glimpse into the future through the eyes of our resident traders. Gaining an idea of new and continuing trends into next year can help to guide chefs and caterers with menu planning to ensure they stay on top of the latest trends with regard to the most popular and on-the-rise fresh produce.”

Top 2018 trends:

1. Black is back
2. Heritage produce
3. Exotic citrus
4. Break-through kale varieties
5. British berries
6. Specialist spuds
7. Named tomato varieties
8. Wonky veg
9. Extravagant salad leaves