The first ever crop of sweet potatoes has been successfully grown in the UK on a farm in Kent after three years experimenting.

Last week about 3t of sweet potatoes were lifted at Hill Farm in Farningham, one of the Watts Farms group’s 10 sites spanning across Kent, Essex and Bedfordshire.

Speaking to The Guardian, group director Joe Cottingham said: “Sweet potatoes have been a challenge but we have finally got there after experimenting with a number of different varieties.

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“We have been successful in growing sweet potatoes outdoors in Kent because of careful variety trial work and selection for frost resistance.”

Sweet potatoes are normally imported to the UK from southern US states, Egypt and Israel because they need warm and dry conditions to grow.

The crop was grown on light land through a mulch, which allowed the grower to get warmer soil temperatures, resulting in a good-sized potato.

Water was supplied using drippers underneath the mulch, which helped plants grow to fruit bearing size in five months.

The business farms more than 600ha growing fruit, vegetable, herbs and salad crops. 

Arable land, polytunnels and glasshouses are used to grow 60 different crops, from bok choy (a type of Chinese cabbage) to extremely hot chilli peppers.

The once highly exotic sweet potato has erupted in popularity in recent years with supermarket Asda reporting sales up 50% in the past year, while Marks & Spencer said sales were up 112% year on year.