Oh yes tons of rhubarb. Yes, jerusalem artichokes, also fuki. Also Chinese artichokes. Gaint bluebells (flowers and leaves are tasty). And yes garlic, best results with Siberian. I also forgot Evans Bali cherry, nanny berry, hawthorn, hascap, and herbs and medicinals. Mushrooms. Lots of wine caps throughout the garden.
You are correct, still zone 3/4. We are about 800 ft above sea level so we are a bit colder and wetter than down the hill.