When trucks can't deliver that Mexican lettuce to New York because they can't buy fuel on non-existent credit, it will be too late. Start now and assure your food independence!

My yard had never been a garden, but does have 24 inch deep topsoil. The bad news is that 30% of the soil is rock larger than a golfball.
Power tools have been very useful, and the rocks will be added to foundation projects. Even if the garden goes back to yard, it will be less trouble to plant a garden without power tools when the time comes.

Getting ones' body used to stoop labor is something that takes a little time. Serfdom doesn't come easy, but fresh fruit is some consolation. Blueberries, raspberries, figs, and grapes don't take much effort once planted.

Prepare to dry, vacuum-pack, or pressure-can your produce. Freezing depends on municipal power service to preserve your food supply (unless you have installed solar/wind/hydro generation and storage in your home). Bad-quality/irregular power may become the new "standard" for electricity.

Water catchment from the roof into barrels provides enough moisture for the 8 week dry season. Our city is inept enough that water may not always flow through pipes & meters.

Birds and opossums are the biggest trouble to an urban farmer. Air rifle, traps, and a .22 pistol have all been handy. Continuous .30 cal. and 12 ga fire are a bit much on a 50'x 100' lot.

Cheers from the intersection of the Willamette and Mighty Columbia rivers.

Ricardo must be rolling in his grave right now.