To frustrated residents of Bray, home of the Fat Duck, the ‘Heston effect’ refers to the expansionist tendencies of the Berkshire town’s most famous son.

The boundary-pushing chef has been buying up pubs in the town of late, like Rick Stein colonising Padstow and Tesco putting its flag pretty much everywhere else.

Today we saw evidence from Waitrose of another startling superpower of the one-time wunderkind – his ability to shift rhubarb, and lots of it.

The upmarket supermarket was unequivocal about who gets the credit for its impressive first-half sales growth – Heston Blumenthal, whose own line is soon to debut at Waitrose, and Delia Smith.

It trumpeted an additional 370,000 visits in the two months immediately after the double-act’s March debut, although like-for-like growth actually picked up pace in the second quarter.

The retailer also again wheeled out a now-familiar stat about 14 weeks’ worth of rhubarb selling in a single week following the duo’s ode to rhubarb and ginger brulée.

Despite the popular saying that you don’t rub another man’s rhubarb, it wasn’t only Waitrose that got an uplift. As The Grocer previously reported, Tesco’s sales doubled after the ad, while Sainsbury’s got a 21% hike.

But in the current climate no other major supermarket can boast of like-for-like growth of almost 4% – or anything close to it.

Parent group John Lewis warned that the second half of the year would see “more challenging trading conditions”. And that was backed up by some worrying official figures released today, showing a shock 0.5% fall in high street sales in August compared to July.

But right now Waitrose has the momentum and with its appetite for expansion mirroring that of its chrome-topped chief salesman, it’s well placed to keep making headway against an otherwise gloomy tide.

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