The dangerous history of allotments

There are now thought to be about six million people interested in having an allotment, with waiting lists as long as 40 years in one London borough.  There have also been huge numbers of words written trying to explain their revival.
 
Perhaps the real question is why they ever went away, given the success of the Dig for Victory campaign in the Second World War, one of the most successful attempts to galvanise the public into action. 
 
There were 1.4m allotments by 1943, by which time over a million tons of vegetables a year were being grown in gardens, parks and waste land.  There were radio programmes (3.5 million people tuned into C. H. Middleton’s gardening slots), even Dig for Victory anthems. By 1970, only a generation after the end of the war, there were only 530,000 allotments left, and a fifth of those were vacant. What went wrong?
 
Perhaps it was the end of rationing in (1954), and the beginning of self-service supermarkets (1950) that ushered in a different sense of plenty.