From what I have learned, it doesn't matter what one calls an allotment leased from the council (community gardens, Bristol grow project, smallholding etc) allotment law as set out in 1950 still applies. It seems there are different laws for the city farms. All the upkeep is the responsibility of the leaseholder, not those who sublet the plots. C has constantly complained that the plot holders don't help in the general upkeep of the field; grass cutting, rubbish removal, planting in general areas such as the orchard etc.
To keep the field in accordance with the 1950's law is a lot of work. It's particulalry a lot of work for someone who has niether the skills, the money or the time and tools to do it. For examples; a decent petrol driven brush cutter capable of dealing with the brambles and heavy weed growth is an expensive item. Most allotment have a rotovator. They're quite expensive too. There is a large industrial skip on the field which is overflowing with bits of rubbish, scrap metal, concrete, netting, all sorts of crap. Now there is also a mound of rubbish around the skip, enough to fill it again. To get the skip removed costs £180.
The point being that C cannot afford to pay for these things and therefore cant comply with the 1950s law.