If possums are damaging ornamental plants or fruit in your garden, build a floppy fence around the garden. Use 80cm wide, heavily galvanised chicken wire, bury the bottom 20 cm and support the remainder on vertical lengths of flexible, high-tensile fencing wire. Bend the wire to curve the upper section outwards. When the possum attempts to climb the fence it will bend over and then spring back. Use collars to protect fruit trees. Recent tests showed none of 15 repellent compounds effectively prevented possums damaging ornamental trees or fruit.
If you trap the possum, it must be released in your yard. If you were to release the possum in another area, it would have to search and compete with other possums for shelter and food in unfamiliar territory. By providing a possum house, you are encouraging the possum to stay and claim your yard as its territory. The possum will then discourage other possums from moving into your roof and yard. By making friends with a possum, you can help to conserve the species and learn about their way of life at the same time.