Any time of year you are likely to be able to find free food growing near you. No matter whether it is the middle of summer or winter, if you look hard enough it will be there.
If you see signs of birds, deer, squirrel, or other critters there is likely something there for you to eat too. I highly recommend finding a book with regionally local edible and/or medicinal plants.
It is mid-February or mid-winter here in northwestern Oklahoma and I am finding plentiful edible greens around camp. This state wildlife area has made several food plots here which have seeded the surrounding forests with winter wheat and hay..
Wandering around the forests here it is hard to go starving.. plentiful oak trees supply acorns and the wild grasses keep the wildlife here fat and happy. It is hard to get lost on the game trails here which interconnect all the hidden food plots.
Edible greens early in the season are highly nutritious.. sprouts can contain up to 10x as many nutrients as their adult counterparts..
Greens are a great source of Vitamin A, C, and K and many other macro and micronutrients.. it is unlikely you will find anything as fresh or healthy in your grocery store market..
It is a little late in the year to find good acorns and pecans, but these would be another great staple for making it through winter here. Most of the small critters like mice and squirrel have already stored up their supplies and rarely have to leave their nests..
Hunting season is mostly over here now, at least for big game, but I wanted to share this example of a fresh deer rub from last season. Adult male deer rub their antler on smaller diameter trees like this one to mark their territory along game trails.
Things like this would get most deer hunters excited to see on their hunting grounds. Not far from here we spooked a small herd bedded down about 20 yards off a food plot..
So my advice is to get out there, get off trail, start identifying edibles, and be comfortable with it. Always continue to learn and share your knowledge with others.