Potato seed stock (2007), from the Soiled series, 16"x20" chromogenic print
SOILED was a year-long project during which I photographed and grew food in my urban community garden.
A note on my methods:
I grow most of my plants from seed, which is cheaper than buying young plants, but requires more time and more labor. Once in awhile I will buy a bag of seedling mix; otherwise, I try not to purchase soil, amendments, or fertilizers. I seek out free sources of straw and animal manure (chicken, sheep, or horse) --which are easier to find than you might imagine --and incorporate these materials into the compost pile in my garden plot. It takes two to three months for me to get a finished batch of compost. I use it to pot up seedlings or as a top-dress fertilizer for plants that are already growing in the ground.
Use what's available:
You do not need to buy a lot of stuff to start growing a garden. Plastic six-packs (for starting seeds) and pots are easy to come by for free; many professional landscapers or gardeners would rather give you their used plastic pots than throw them in the garbage. This has the additional advantage of keeping a manufactured item in continued use rather than adding it to the landfill. This concept has been called "interrupting the waste stream."
How much space does it take?
The statistics I've read say that it currently takes commercial agriculture 15,000 to 30,000 square feet to raise all the food for one person for a year. In his book "How to Grow More Vegetables," John Jeavons details techniques that may allow a gardener to grow their years' supply of food on the equivalent of 3403 square feet. (Jeavons, 1974, 2002)
An all-garden meal:
I don't grow nearly all of my food in the garden. There are some times during the year when I can eat a few all-garden meals. July is one of those times. If you read seed catalogs enough, you'll notice that they will often bring up the idea of adding variety to the crops that you plant. This is because some of the most successful crops are so productive that you might even get tired of eating them. I expect that this is why somebody came up with the idea of stuffing squash blossoms and making bread/cake out of zucchinis. Pickling is also a way of dealing with seasonal surpluses, and ensures that you will have some vegetables to eat during the winter.
Less space than it takes to park a car:
My garden measures about 7' x 14' (98 square feet). The standard metered on-street parking space in San Francisco measures 7'x20'.