Use a tape measure to measure around the tree truck near the ground.
Cut the field tile with box cutters so it measures about a foot tall and is a few inches wider than your tree.
Use the box cutters to poke a line of holes down the length of the field tile's two short sides.
Dig about an inch into the ground around the tree using a spade, being careful not to damage any tree roots.
Wrap the field tile around the tree and into the dug-up area around the tree.
Pack the loose dirt back into the hole around the tree.
Feed cable ties through the holes on both sides of the field tile and secure each cable tie.
Check your enclosure periodically to be sure your tree is not outgrowing it. Create new enclosures as needed.