I work in the city of London, not exactly an area with a lot of allotments or large gardens for growing veggies, you see the odd grow bag on a balcony but that's about it.
Last week I had to spend some time on another company site, the walk to which took me through the backstreets of Whitechapel and Shadwell on the way to Wapping.
On a fairly busy road I passed a row of new town houses which don't appear to have any kind of garden and just a small paved yard at the front. This doesn't seem to have stopped the owners from growing their own veggies though, quite a range of pots and crops packed in there among the wheelie bins.
Proof that you don't need a massive space to produce your own food.
If you ever find yourself in Wapping I highly recommend the Captain Kid, Town of Ramsgate and the Prospect of Whitby down on the Thames path.
Cheers and happy gardening folks!!