Thought of another free harvest that I think might grow in your area. Mulberries. If so, look NOW, because being a little south of me, I think your trees might be just about finished bearing.
Take with you shallow containers, as mulberries are very fragile. They bruise under the weight of a second layer of berries very easily. I like to collect them directly into colanders so that I won't toss them about so much going from field to kitchen. They are most tasty in years when there has not been a lot of rain at ripening time. Otherwise they seem to take on enough water to dilute the sugars. But I'm sure they would still have some nutrients even when not so sweet. I guess you could add a little white sugar to them if it has been rainy.
Not only are mulberries fragile, but their attachment to the tree when ripe is fragile. All you have to do is touch the berry and it falls off in your hand. One time I went out with a little girl and we stretched a sheet below the branches of a small tree. We staked the sheet so that it was like a fairy trampoline under the tree. Then we shook the tree and let the berries fall, cushioned, into the sheet. We still had to sort out the not quite ripe ones and the past ripe ones.
Mulberries do not keep well in the fridge or out of the fridge. They dehydrate quickly. So you should expect to eat them right away. You can use a bit of the juice to color white frosting, (Once I tried them as a fabric dye, but by themselves, they did not make a permanent die. Kids can make a water color paint, but that doesn't help your food budget.)
