Is this a grapevine?
I've had a particularly fast growing vine climbing a chain link fence for the last few years. I've thought it was better looking than the fence, so have just let it be. Looking at it more closely today, I've noticed clusters of purple blue berries growing on it, and the stems of these berries look remarkably like grape clusters. The leaves are clusters of 5 to a stem, oval with a slightly serrated edge, and dark green. The vine seems thick and tough, with finer tendrils, but ultimately will break with little pulling force. The berries at this point look like small blueberries, with a seed and milky fluid excreted when crushed. Input would be appreciated!
Arapahoe County Colorado
No, probably not a grapevine.....but it sounds like a relative of grape called Virginia Creeper (Parthenocissus quinquefolia). 1/4 inch berries are eaten by birds (but you should not eat them) and then the seeds are pooped out. They germinate readily after traveling through the bird's gut.
Virginia Creeper berries ripen to turn blue-black in mid September.
Tendrils have "adhesive disks" at the end that allow Virginia Creeper to attach to and climb vertical surfaces (like the outfield wall at Wrigley Field in Chicago).
Virginia Creeper leaves turn rusty to bright red in October before falling.
Photos would help us be more sure of this vine's identity.