Cover the immediate area with a layer of mesh poultry wire. Any sheet of metal mesh will work, as long as the holes are 1 inch or smaller.
Insert the mesh fencing at least 6 inches into the ground at all sides since squirrels may attempt to dig under the fence. Drive as many stakes as necessary into the ground to hold the mesh in place.
Set up an electrical fence with at least two electrified strands to deter squirrels. The electric wires must be positioned at least 3 inches from the mesh. One electric fiber must be 3 inches off the ground, while the other must be the height of the fence.