Jennifer Schultz Nelson
Extension Educator, Horticulture
I've concluded over the past few weeks that the old sayings are true–beauty is in the eye of the beholder, and one man's junk is another man's treasure. Recently, I have had several questions on Osage oranges, or hedgeapples. The typical one is "How do I stop my tree from dropping all these ugly #$%* fruits in my yard?" A question that surprised me was "Where can I get Osage oranges?" I had to make sure I was hearing the person correctly. They actually wanted Osage oranges?
It turned out the person wanted to use Osage oranges as an insect repellant for their home. This is a popular home remedy for the bumpy green spheres, but does it really work? There is some evidence published by Iowa State that oils isolated from Osage orange do indeed repel the German cockroach.
But of course, there is a catch. The researchers painted surfaces with the Osage orange oil, and observed what happened when the roaches were given a choice to occupy the oil-covered or untreated surface. They are quick to point out that their experiments used extracts, and not whole Osage orange fruits, as the folk remedy suggests. By far, the roaches preferred the untreated surface. But what was in the oil to repel the roaches?
Further research identified sesquiterpenoid components of the oil believed to be responsible for repelling the roaches. Sesquiterpenoids are part of a larger chemical group called terpenoids, which are naturally occuring aromatic compounds. Terpenoids are composed of repeating units containing five carbon atoms--sesquiterpenoids have fifteen carbon atoms in each molecule.
Terpenoids may be an unfamiliar term, but many extremely familiar scents, colors, and flavors occur because of terpenoids. Terpenoids contribute to the familiar scent of eucalyptus, yellow pigments in plants, as well as the familiar flavors of cinnamon, ginger, menthol and cloves.
Many compounds in this group are being investigated for potential pharmaceutical and antibacterial use. Interestingly, Iowa State researchers have received a patent for using the sesquiterpenoids isolated from Osage orange as a natural insect repellent.
Does this mean we should fill our homes with Osage oranges this fall? Probably not, since the researchers used extracts, not the whole fruit. But if it makes you feel better, it probably won't hurt anything. They are non-toxic, and supposedly, they taste like citrus peels. The only potential health risk listed is that sap from the fruit or tree can cause contact dermatitis in some people.
There have been some accounts of cattle dying after eating hedgeapples, not from poisoning, but from choking on the large fruit. Researchers hypothesize that a giant sloth that roamed North America thousands of years ago was a regular consumer of Osage oranges.
The Osage orange tree, Maclura pomifera, is a member of the Mulberry family and native to an area of the central U.S. that includes parts of Texas, Oklahoma, and Arkansas. The Osage orange tree is dioecious, meaning there is a male and female tree. The male tree's flowers pollinate the flowers on the female tree. It is then only the female tree that produces the fruits. Both male and female trees are covered in half-inch long spines.
The common name 'Osage orange' comes from the fact that the Osage Indians lived in this region. Samples of Osage orange were the first tree samples sent to President Jefferson in 1804 by Meriwether Lewis, during his expedition to the west with William Clark.
The Osage Indians used Osage orange wood to build bows. This common use led French settlers to call the tree "bois d'arc" meaning "wood of the bow". The Osage orange is still considered by many to be the finest wood for bow-making, and one of the most durable woods available.
Its extreme hardness makes it somewhat tough to cut and shape, but the results can be absolutely beautiful. The wood starts out a golden yellow, but quickly darkens. Osage orange wood is used for tool handles, fence posts, harps, bird calls, and utensils. Some of the most gorgeous wooden bowls I've ever seen were carved from Osage orange wood. It is very dense and makes excellent firewood burning very hot, comparable to a coal fire. Several Master Gardeners warned me though, that the wood tends to throw sparks much like fireworks, so it is best burned while contained in a wood stove rather than a fireplace.
Osage orange probably would have stayed in its native region if it weren't for livestock farmers. They found the trees were remarkably disease-free and tolerated a host of extreme conditions. They purposely planted the trees as living fences on their property. The trend spread across the Midwest. When pruned, the trees formed thick hedges that were nearly impenetrable because of the numerous spines on the branches. The practice of planting Osage oranges as barriers died out with the introduction of barbed wire for fencing. Remnants of the old Osage orange hedges still linger on many farms today.
Osage orange is a very hardy tree, but usually not a good choice for a home landscape because of the potential for tons of hedgeapples each fall and ever-present thorns. There have been some cultivars developed such as 'Witchita', 'White Sword', 'White Shield', and 'Park' that are thornless and guaranteed male, eliminating the possibility of fruit.
If you should plant a thornless, fruitless cultivar and find you miss the knobby green fruits, be comforted with the fact that many entrepreneurs are willing to sell Osage oranges to anyone willing to pay for them. I have seen them sold in several places recently for decoration–one seller even touted his three for ten dollar hedgeapples as "organic", trying to make them even more appealing. Craft diva Martha Stewart touts their value for craft projects, encouraging people to dry them for arrangements. A quick internet search brings up several sites selling Osage oranges for decoration or their reported insect repellant properties, including the ever-popular eBay.
I was amazed that there was a market for hedgeapples and thought "What's next? Selling sweet gum balls?" Sure enough, they're on eBay already!