It can be no coincidence that two major supermarkets simultaneously launched organic box schemes ahead of Organic Fortnight, which ends tomorrow. First Sainsbury's, then Tesco, announced that they would be trialling regional schemes - and now Ocado has joined the fray.

Of the three offers, Tesco's is the most generous. It said it could provide ten items of seasonal vegetables for £11, compared with Sainsbury's eight items for up to £15. Ocado offers a wider range, but a comparable ten-item box would cost £14.

All are certified by the Soil Association and focus on seasonal British produce. But will customers warm to the idea of buying a slice of the countryside from the multiples?

The competition thinks not. Marketing manager Andy Johnson at farmer-run box scheme ­Riverford Organics says: "People choose us because of our strong emphasis on local production and because they know where our food comes from. The multiples want a piece of the action - they are not doing it for the good of the landscape."

Other providers have a similar message. Ella Heeks, MD of Abel & Cole, says customers and non-customers alike are vowing not to take up the supermarket scheme. "We've had a lot of support from people who are interested in where their food comes from," she says.

The Soil Association has rated the supermarket offers against independent schemes. While a good box scheme scores 16 points, the supermarkets score just four on the grounds that they fail to invigorate local economies or to engage consumers with producers.

Director Patrick Holden advises: "The Soil Association would always encourage consumers to support their local organic box scheme first, but if there isn't one in their area, supermarket schemes could be useful in meeting the demand."

Sainsbury's vegetable buyer Russell Crowe thinks it can compete on an ethical as well as commercial front. He says take-up of a pilot scheme in 11 stores around Cambridge has already exceeded expectation. "This is a huge push for the UK organic industry. We are able to draw together the best product by using our national network of growers."

Efforts by retailers to get into veg boxes have foundered in the past, most recently with Safeway in 2001. But that was before internet shopping was established and relied on shoppers buying it off the shelf.

It is a key difference, according to Tesco organic veg buyer Emma ­Pettitt. "Customers tell us they want us to make it easy for them. We know there is demand for fresh, seasonal organic produce delivered with the rest of an online shop."

The massive growth of organic could also make the supermarket venture a surer bet. Sales rose to almost £1.6bn in 2005, according to the Soil Association [Market Report, 52 w/e 31 December]. And Tesco claims its organic sales have grown 70% since it placed organic and conventional produce side by side.

There are other reasons why this latest box scheme is different from earlier efforts and should be taken seriously by the competition. Gone are the days when 'seasonal' meant a grim array of cabbage, cauliflower, carrot and potato. New techniques have extended growing seasons and introduced new crops to the UK. As Tesco's Pettitt says: "We believe it will encourage consumers to experiment with different produce - under the assurance that it is all of the highest quality."