Unroll a length of chicken wire to encircle the fig tree.
Drive garden stakes into the ground opposite each other just outside the ring of chicken wire. Position the first stake at the point in the circle where the ends of chicken wire meet. Attach the stakes to the wire with twine, looping the twine in through the chicken wire and stake several times and then tying around the stake at several points along the length of the stake to secure the wire cage in place around the tree.
Drop dry leaves into the wire cage from above, letting the leaves settle around the trunk of the fig tree as insulation.
Wrap burlap around the wire cage, securing in place by wrapping connected bungee cords around the outside.
Seal in the top of the tree by placing a bucket over the top of the cage. Hold in place with additional bungee cords, if necessary.