A few months ago I was walking on our quiet street when I noticed a neighbor collecting green things by the stream. She had no idea what the name was and only said it was common in her country and it made a good cooked soup. I was a little leery and didn't want to encroach on her territory but eventually got curious enough to track down the name and taste. Watercress! Makes a fabulous omelet, sandwich green, salad, and I use the stems in soup (another use of the vitamix)
Another thing I've been foraging for years is various berries. Wild blueberries are a frequent sight iin cities and parks because the trees aren't that tall and attract birds. Mulberries, a purple stained invader. Our backyard has the much maligned wild blackberry, very seedy but makes a fetching sorbet with the vitamix. Then there is the invasive wineberry, which is wild raspberry. In past years I've picked gallons in the 4 weeks it matures locally, eating fresh and freezing. I think o raspberries as both healthy and luxurious. My parents are not into any of the wild fruit because of the seeds, which I empathize with (but: free!)
Anyway, this problem was overcome recently with the discovery of a small notice on the package of Driscolls strawberries. Basically if you review the berries, they send you discount coupons, which I combine with local stores doubling policies to get them at a rock bottom rate. I don't mind the surveys, mindless enough to do it, and it means I can justify eating fresh berries all year round. My parents have finally gotten out of the "too expensive to indulge in" habit when I point out that its now cheaper to eat raspberries than apples.