This time of year (or soon) there is wild asparagus. If you walk along the shoulder of rural roads you can find it. Late summer the plant is in it’s mature state and is easy to recognize even driving in the car. Because it is a perennial you can mark it on a map and go back in the spring to cut it in season.
If you have a topographical map of your area you can mark all of your findings and other important info for later use.