Money can't buy these unless you're at the right place, at the right time

Beet greens are among the few truly seasonal vegetables. We never see them in the stores, but, courtesy of the South Austin farmers' market, we enjoyed our annual treat, complete with baby beets attached. In the old Fannie Farmer cookbook (this was the very edition, 1918, that I knew as a kid), the instructions are to boil them for one hour [!] "or until tender," but we've never eaten any but young ones and they need to be cooked just until wilted.