Italian immigrants brought broccoli (Brassica oleracea italica) to America in the early 1800s, and gardens haven’t been the same since. And that’s a good thing. Can you imagine life without broccoli?

When I first grew broccoli raab in the 1990s, I figured I was doing something wrong. I liked the way it produced small shoots rather than big heads and that edible leaves, stems and buds were all part ...