Allotments v Farms

I think an allotment is pretty packed compared to garden growers? I don't grow anywhere near that and never have but I pop to our local allotments occasionally to see a friend. He has been growing on his for about 10years and not an inch of space is wasted.

# how much can you crop from a rhubarb? I've got 5..there's a fair amount in a couple of sticks and it keeps on coming. We take stuff like that for granted?