I live in a hotter climate and one of my favorite combinations is an eastern redbud (Cercis canadensis) or western redbud (Cercis occidentalis) as the center of a small food forest. It is a member of the bean family, and I eat the seedpods green and cook the seeds (much like lentils). Since it fixes nitrogen and provides nice lacey shade in very hot summers, I find that everything grows well underneath. It has lovely purple-pink blooms in early spring and attracts pollinators. In my Texas garden, I had an existing eastern redbud and ate the pods and dried seeds. Redbuds are beautiful trees for a small garden and still provide food. Mine had a bench for sitting and I planted a mix of flowers and vegetables underneath... I like perennial edibles underneath, especially wild violets (Viola canadensis) for nearly evergreen perennial salad greens in Texas as well as beautiful purple blooms in late winter. I also grew these in Seattle since they are native to most of the U.S. You can buy viola canadensis, but I think the wild ones taste better. They are also good in deep north shade or under shrubs. Another good one is Sorrel (Rumex acetosa). I add a few daylilies, their buds are quite tasty, and the bulbs are edible if they need thinned. I make a circle of native onions around the outside, and pull them for onion greens. In summer, I hang tomato plants upside down from the branches and because Texas is so hot (tomatoes don't set fruit above 95 degrees), the light shade keeps them in production longer. In the winter, I fill in with english peas.
I love small scale gardening this way, and just planted a serviceberry (Amelanchier alnifolia) that will become part of a food forest in my mountain garden I am starting in New Mexico. I get considerably less water, but am berming and burying wood underneath my plants. I have 5 acres of pinyon juniper forest, with a few empty spots, which are being filled with fruiting trees. I have a couple pinyons close to my house and am using them as a different grouping.
