Annual sales of organic food and drink in the UK have hit £2bn, according to a report by the Soil Association.
People in the south of England are the UK's biggest organic food fans
However, supply of home-grown organic food is not growing fast enough to meet demand, said the organisation, which certifies organic food.
Spending on organic products grew 22% between 2005 and 2006, making the UK the third largest market in Europe behind Germany and Italy.
UK supermarkets saw their slice of organic retail sales rise by 21%.
And people in London, the south east, the south west and Wales were the biggest spenders on organic products.
Price rises expected
For the first time, sales of free range and organic eggs topped those of eggs from caged birds, the report said.
Vegetable boxes, mail ordering and other local supply schemes were among the big winners of 2006, with sales growing by 53% to £146m.
"It is important to note that the rate of growth in the organic retail market is unlikely to be sustained in 2007 due to a severe shortage in the supply of UK organic products." The amount of home-grown organic grain, used to feed livestock, slipped in 2006, resulting in more imports.
The Soil Association's director of food, Helen Browning said that the price of organic food at the till would probably rise as grain prices climbed.
"The significant short-fall in UK grown organic cereals is a major concern, forcing greater reliance on imports for livestock feed but of course, it is also a major opportunity for current non-organic cereal farmers to convert and supply a guaranteed and growing market," she said.
The high cost of rearing organic pigs saw the number of them being slaughtered falling by 10%.
Organic fruit and vegetable production is also undersupplied, according to the report.
At the end of 2006, the UK had more than 4,600 organic farms, up 1.6% on a year before.
Earlier this year, the Soil Association said that it was considering stripping organic status from food flown into the UK.