This...
...and this are where I was doing all my vegetable growing before I got my allotment in October 2010. Over the months I tried lots of different ways of increasing the space.
Hanging baskets (lined with old compost-bag) can grow great salad...
And later be used for strawberries and tomatoes.
'Tumbling Tom' provided us with cherry tomatoes for months.
Salad baskets work even in quite unpromising sites, such as this shady corner of our house.
Tip: use big jubilee clips to fasten baskets to a drainpipe.
Blue mushroom trays, also lined with compost bag, are also deep enough to grow lettuce. One less bag of supermarket lettuce!
This long bag, sold at garden centres for bedding plants, also grew great lettuce - for a couple of months. However the compost settled down and compacted, so in the long term it wasn't something I continued with.
A herb-filled window-box with salad pots hanging along the edge. They are actually Ikea cutlery drainers! Get your eyes focused on anything - especially free/cheap things - which could be used to grow in.
Containers dry out easily, so I needed to anticipate the weather and drape fleece over the salads especially.
By August there are tomatoes, courgettes, chillis, and potatoes in bags.