I had a problem with raccoons one year,I ran a single electric fence wire about 4 inches off the ground on the perimeter of the garden.That kept them out.Should work on woodchucks too,I just shoot them here.
LOL. Electric would be fun. The ground hogs burrow beneath the fencing though. About the only thing that we haven’t had trouble with is raccoons. I wonder why ... it is odd considering.
A neighbor put up an electric wire around his tomato plants one year, because of raccoons. I guess his pup thought it was a fire hydrant. LOL