Horse apple trees, also known as Osage oranges, are not difficult to grow. Despite their name, the fruit on these trees are neither apples nor oranges. Horse apple trees are actually a member of the mulberry family and they are very easy to grow if you live in United States growing zones four through nine. These trees are most famous for their big, green fruits. The seeds of the fruit are edible, but they are better known as natural insect repellents. Research at Penn State shows that horse apples actually have a tiny amount of chemicals that will repel cockroaches, demonstrating that there might be some truth to these claims.
Horse apple trees will grow almost anywhere and used to be planted by farmers who wanted a natural barrier for their livestock before barbed wire was invented. If you want to grow your own horse apple tree, find it a spot in full sun or partial shade. Keep in mind that once it is full grown, your tree should be 40 feet high and another 40 feet wide. Horse apple trees like neutral, well-drained soil. They do not need to be pruned and should be watered on a regular basis. If you want to, you can give your horse apple tree an all-purpose fertilizer in the early spring.
There are a few things for you to consider before planting a horse apple tree. First, the horse apples, which are green and grow to about six inches in diameter, will make a huge mess in your yard every year. This is especially the case once squirrels get to them. Second, these trees have spines. They were once used as a substitute for barbed wire. Be careful when you handle them. Finally, if you have an actual horse, under no circumstance should the horse have access to the horse apples. Horses have been known to choke to death on these hard fruits.