Here in SW Washington, we purchased one of the largest cul de sac lots with a house in this 120 lot subdivision. Flat topography, Mediteranian weather pattern.
At first I thought that I could grow a fairly large garden of a variety of field crops as well as fruit trees.
the only crops that I had actually harvested was radishes, leaf letuce and cherry tomatoes. Anything else had marginal success to complete failure. So NOT worth growing. Then I found out that this whole subdivision was built on top of a former swamp land. The developer had braught in ruble rock, then toped it off with truckload upon a truckload to any dirt that he could find from commercial building sights... ie. clayee to hardpan , to rocky soils. So, I dug a dry creekbed from the very back corner to the front yard sidewalk neat the driveway for drainage and used that dirt to make hills 2-3 feet tall and enclosed them with 100-700 boulders. I then mixed in peat moss, sand, and composed. Worked well for 4 years, that is until this year. when I noticed that those hills bad become waterloged from 3 weeks of rainfall and plants there were turning yellow. They were DROWNING ! So, on the front hill I dug 8 French drains around it's perimiter, mixed in sand and compost, then replanted some of the Himalayan ferns, Mugho pines and corral bells. In the back yard, I dug another dry creek bed ( lined it with river rock up to 12" diameter and installed pond pebbles consisting of pea gravel to round rock up to 2" dia. along a large hill for additional drainage ( water flowed for 2 full days from the bottom of that hill's sides into the new dry creek bed, so working now ) . I will have to .do quite a bit more of additional diging for more drainage and planting ornamentals. Store purchased food it is , since conditions on this property are NOT condusive to produsing self sustainind food supply by any streatcth of imagination or wishful thinking.