Peter Marks vaunted products like Co-op's Grown by Us range of strawberries, potatoes, peas, onions and pumpkins in his speech last week at the British Library.
He blamed the economic collapse on a "catastrophic failure in ethical spending" at the Fair and Square conference on ethical consumerism earlier this month.
"Customers now want value and values without compromising on price for ethics," he said. He added that failures "at the heart of our businesses" had landed the UK in the "mess we're in".
Co-op's ethical spending rose 15 per cent this year to £35.5bn, he said. Green home spending rose 13 per cent to £6.7bn. Co-op was committed to supporting regional growers and its vision was to be "Britain's favourite community retailer", he added.
"We might be in a recession but we will not be abandoning our fair-trade suppliers when they need us most and I'm confident our customers will support this."
Co-op claims to be the UK's largest farmer, controlling 30,000ha of land in England and Scotland for peas, cider apples and strawberries. In June it launched a Truly Irresistible English Apple Crush drink.