Unexpected: Waitrose announced yesterday the early arrival of its first British tomatoes of the year . Our glorious spring has accelerated the growing season - and supermarket shelves are already bursting with English summer fruit and veg. Usually at this time of year we would still be eating vegetables imported from Spain and South America. But thanks to endless days of sun and temperatures we would not expect until August, English tomatoes and asparagus are already on the shelves, weeks ahead of usual. Waitrose announced yesterday the early arrival of its first British tomatoes of the year. It is stocking large Jack Hawkins, aromatic Red Choice and tiny Baby Plums, all grown in greenhouses across England. And the supermarket has been stocking asparagus since the beginning of the month. Strawberries are also already on the shelves - far earlier than normal - and English raspberries saw their earliest ever appearance in the last week of March. Morrisons, meanwhile, yesterday predicted Britain would have best crop of asparagus for nearly a decade. The chain estimates that the asparagus crop could be up 20 per cent this year compared to average, having received an early boost of high light levels and warm temperatures. Morrisons asparagus buyer David Bartle said: ‘Growing conditions look like they are going to be perfect. ‘The good weather will not only affect the amount of asparagus grown but also the quality of the crop. We could have the most exceptional year since 2007.’ Peter Cooke, Waitrose vegetable buyer, said: ‘Our customers can choose from a wide variety of home grown tomatoes and in bigger quantities than this time last year.’ The sunny spell is set to continue until later this week, when the weather will take a turn for the worst. The mercury is set to hit 21C (70F) as the Queen celebrates her 89th birthday today (Tuesday) - making it hotter than Ibiza, Athens and Barcelona. But rain, cloud and cooler temperatures are predicted for the second half of the week. Early arrival:  thanks to endless days of sun and temperatures we would not expect until August, English tomatoes and asparagus are already on the shelves, weeks ahead of usual . Showers could hit the capital this Sunday as tens of thousands of runners take part in the London Marathon. Dan Williams, a spokesman for the Met Office, said most of Britain basked in sunshine yesterday and will continue to enjoy good weather until Wednesday. He said: ‘There has been lots of sunshine around and the temperatures have been pretty decent for this time of year - temperatures have hit 19C in Sussex and 18C in London. But he added: ‘By Thursday a lot more cloud will be around in general and there will be light rain over Scotland. ‘For most it will be a dry day still with some sunny spells, but generally that cloud is the herald of slightly more unsettled weather. ‘The high pressure that has been dominating for the past few days moves over and we see a bit more of what you would expect this time of year.’
Usually eat vegetables from Spain and South America at this time of year .
But recent temperatures have led to English tomatoes sprouting early .
Strawberries and raspberries also on shelves already, far earlier than usual .