Hedge apples are the fruit of Osage orange trees. The trees are related to mulberries and were used as fences and hedgerows by farmers before barbed wire became commonplace. The fruit is citrus-scented and believed by some to have insect-repelling properties.
Hedge apples are about five to six inches in diameter, green to yellow-green in color. They ripen between September and October and fall to the ground. Few animals seek the fruit but squirrels enjoy the seeds once they open the fruit's tough hull.
Some people put hedge apples around the foundations of their homes, along windows and toss a few into crawl spaces or basements. Legend says that this practice is effective as a deterrent for spiders, cockroaches, crickets and other insects.
Iowa State University discovered that hedge apples contain a chemical substance known to repel cockroaches. However, the university was unable to determine that the fruit as a whole was able to repel insects or control insect populations.