Apples are a big one for me, though sadly many of our local trees are dying. Also pears, cherries, apricots, juneberries, pawpaws, and black raspberries. Lots of spring greens and edible "weeds" – lambsquarters, wood nettle, etc. Mushrooms of course (we get black morels coming up in the yard most years).
Don't forget black walnuts if they're near you. Most people around here consider them a nuisance, yet the meats sell for about $16/lb at Whole Foods! It's a high value crop despite the work involved. The shells will burn well in just about any pellet stove. Once composted, the husks are an excellent fertilizer for grass or anything that's juglone tolerant. I have fantasies of separating out the abundant husk fly maggots and using them as an aquaponics input; haven't quite figured that one out yet.
We have hickories and hazelnuts too, but somehow the squirrels always seem to get to them first.
However much I love being close to Nature, I have to admit that my number one highest value forage is... college students' garbage ;-)
How do you harvest black walnuts? I tried once and just made a stained mess everywhere. If I recall, a sticky nasty mess....
Not the original poster, but I also use them (though I've yet to find any on this property, sadly). I try to get the outer husks off or mostly off right after I gather them from under the tree. I roll them around under my foot on a hard surface to smush of the husk (learn from my mistake and don't do this in white tennis shoes - they'll stain, permanently). Then, either pick up the nuts with gloves or resign yourself to stained fingers for a few days. I usually gather some of the husks to make a dye with (I did my hair with it for a while).
I let the nuts dry out well so that the staining isn't an issue anymore - do this in a single layer if possible or stir frequently to keep air circulating and limit mold. If you got of all the husk, or very nearly, you can store them for several months when dry, or even a year or more in the freezer, right in the shells.
To crack them, you need a great deal of force, and to do it neatly, that force needs to be carefully controlled. So, hit them with a hammer and pick out the meat in bits if you don't mind the occasional sticky mess - there's an art to hitting hard enough but not too hard. Better and more reliable, though, is to use a vise, the kind that mounts on a work table. You can figure out just the right angle to stick the nut in there, crank it down, and get true walnut halves.
It's a lot of work, clearly. In my foraging I've come to accept that free protein that doesn't run away and doesn't cause flatulence is a lot of work. :)
