With their innate climbing abilities, it is almost impossible to keep squirrels from getting to fruit trees. In order to be effective, you will need to start early—before the squirrels come to think of your trees as a food source. Barring that, expect to use several methods at the same time, starting with a basic tree guard and then moving on to some extra methods. As you do this, remember that the magic number will be “6 to 8 feet.” That is the average jumping distance for most squirrels. Anything within this range is fair game for a squirrel.
Basic Tree Guard
Wrap a 2-foot band of sheet metal around the trunk so it is about 6 to 8 feet off the ground.
Fasten the metal into place by wrapping wire around the trunk and attaching the wire to springs. The springs will allow the metal to expand as the tree grows.
Repeat steps 1 and 2 for any branches that are below 6 feet on the tree or trim the tree so no branches hang below that point.
Make sure no other trees are close enough to provide an alternative access. If there are, trim the branches to provide significant distance between the trees or wrap metal around the other trees as well.
Look around your trees for alternative access methods the squirrels may use. Any other trees, buildings, wires, poles or similar items within 6 to 8 feet of the trees may be used.
Cover telephone and electric wires with long plastic tubing to discourage squirrels from using them.
Trim branches that are close to buildings so there is a distance between them of 6 to 8 feet.
Install a squirrel feeder and keep it stocked. Squirrels will follow the path of least resistance. If they have easy access to food, they will not bother to scale your trees for it.
Cover the trees with plastic bird netting. Although squirrels can chew through the netting, it will deter them if they use other trees or buildings to gain access.
Apply taste repellents. According to Cornell University Cooperative Extension, the active ingredient in hot peppers, capsaicin, has been a proven (but not 100 percent) deterrent for squirrels.
Hang mothballs around the tree and sprinkle them around the base of the tree. To hang in the tree, place the mothballs into a piece of nylon hose about 1-foot long. Some brands, such as Enoz, work better than others.