There's an art to hiding things in plain sight.
You've seen my garden.
Most years, even the nine footers are screened from my neighbor's view, unless they are standing on their roof.
Much of that screening is done with vertical gardening. Training pole beans, tomatoes and cucumbers on 7' remesh works wonderfully. Shrubs, trees and trellises work, as well.
This is much more stealthy than building a 16 foot block wall around your property.
With prop 215, I've become a little less paranoid. My neighbors are aware of my garden, so I don't worry about them. Both are in their 70's and know I know they know.
One neighbor is very helpful, providing me with all his grass clippings, which I use for mulch and compost.