Giant strawberries 'you cannot fit in your mouth' are coming to UK supermarkets following an unusually warm and dry British spring

They're an iconic part of the Great British summer – and they're getting a lot bigger.

Huge strawberries are soon coming to UK supermarkets, experts have revealed. 

The 'whoppers' are so big you 'cannot fit them in your mouth' – but they have not been genetically modified.

In fact, an unusually warm and dry British spring has caused the berries to swell to nearly twice their normal size – just in time for Wimbledon. 

The Summer Berry Company, a strawberry farm near Chichester in West Sussex, supplies major retailers, including Tesco, Sainsbury’s, and Marks & Spencer. 

Bartosz Pinkosz, operations director at the farm, said he has 'genuinely never seen a harvest produce such large berries consistently' in 20 years. 

'Some are supersized – growing to the size of plums or even kiwi fruits,' he told the Guardian. 

'It has been a perfect start to the strawberry season for us.' 

Generally, strawberries – the fruit of the Fragaria plant – need plenty of sunlight and dry conditions in order to thrive. 

They prefer between six to eight hours of sunshine during the day – which is why British-grown ones are so hard to find during the winter – and cool conditions during the night. 

Cooler nights allow strawberry plants to put their energy gained from the day into producing more natural sugars, according to British Berry Growers. 

So although bigger strawberries are not necessarily sweeter, the combination of warm days and cool nights in the past few months has been perfect for the fruit. 

A hot spring followed a dull and cold March allowed plants to develop strong root systems, according to Mr Pinkosz. 

'We had the darkest January and February since the 1970s but then the brightest March and April since 1910,' he said. 

The grower estimates that the strawberries currently growing at Summer Berry Company are between 10 per cent and 20 per cent larger than usual. 

The 'giants' weigh about 50g, while the average is 30g, so although they're not quite twice the size you may need a few bites to eat them. 

Pauline Goodall, another strawberry farmer in Limington, Somerset, also said a warmer than average start to May has made the fruit bigger than usual. 

'They're just ripening at a phenomenal rate,' she told the BBC. 

Nick Marston, the chair of the industry body British Berry Growers, said there's 'an average involved' so some crops will be slightly smaller than others. 

But the 'very nice sunshine' cool overnight temperatures 'are ideal for fruit development,' he told the Guardian. 

'We're seeing very good size, shape, appearance, and most of all, really great flavour and sugar content, which is what consumers want when they buy British strawberries,' he said. 

Meanwhile, Marion Regan, managing director of Hugh Lowe Farms in Kent, said a 'glorious spring' has created a 'good size' strawberry crop with plenty of sweetness. 

However, she cautioned that the strawberry growing season lasts until November, so it remains to be seen what conditions will be like in the near future. 

Strawberries are temperate crops (adapted to cooler climates) and can stop bearing fruit when growing temperatures exceed 28°C (82.4°F). 

It's why some scientists are concerned that hotter temperatures of the future could threaten strawberry crops. 

Last year, a University of Waterloo study found strawberries could be fewer and more expensive because of higher temperatures caused by climate change.

The researchers found that a rise in temperature of 3°F (1.6°C) could reduce strawberry yields by up to 40 per cent. 

'There is an urgent need for farmers to adopt new strategies to cope with global warming,' warned the study authors. 

Strawberries are not only a high-demand fruit but they have a 'notoriously short shelf life' – two factors that can bump up prices if conditions are not right.