While many Iowans have undoubtedly seen the yellow-green, grapefruit-sized fruit at farmer's markets, supermarkets, garden centers, and other locations, few individuals know much about these rather unusual fruit. Questions abound. What are they? Where do they come from? Are they good for anything?
The Tree and Its Fruit
The yellow-green fruit are commonly call "hedge apples." They are produced by the Osage-orange (Maclura pomifera). Other common plant names include hedge apple, bodark, bois d'arc, and bowwood.
The Osage-orange is a small- to medium-sized tree. It commonly grows 30 to 40 feet tall, occasionally as tall as 50 to 60 feet. It typically has a short trunk and a rounded or irregular crown. The leaves of the Osage-orange are a shiny medium to dark green. They turn yellow in the fall. The twigs are buff to orange-brown and are armed with 1/2-inch long spines. The stems exude a milky sap when cut. The Osage-orange is dioecious. Male and female flowers are produced on separate trees. The small, green flowers appear in May or June. The female trees produce 3- to 5- inch-diameter fruit which ripen in September or October and fall to the ground. The "hedge apple" is an aggregate fruit composed of numerous one-seeded druplets. The Osage-orange is a member of the Mulberry or Moraceae Family. Other cultivated members of this family include the mulberry and fig.
Native Habitat and Current Distribution
The Osage-orange is native to a small area in eastern Texas, southeastern Oklahoma, and southwestern Arkansas. This region was also the home of the Osage Indians, hence the common name of Osage-orange. White settlers moving into the region found that the Osage-orange possessed several admirable qualities. It is a tough and durable tree, transplants easily, and tolerates poor soils, extreme heat, and strong winds. It also has no serious insect or disease problems. During the mid-nineteenth century, it was widely planted by midwest farmers, including those in southern Iowa, as a living fence. When pruned into a hedge, it provided an impenetrable barrier to livestock. The widespread planting of Osage-orange stopped with the introduction of barbed wire. Many of the original hedges have since been destroyed or died. However, some of the original trees can still be found in fence rows in southern Iowa. Trees have also become naturalized in pastures and ravines in southern areas of the state.
Uses of the Osage-Orange
The wood of the Osage-orange is golden yellow or bright orange when first cut, but turns brown on exposure. The wood is extremely hard, heavy, tough, and durable. It also shrinks or swells very little compared to the wood of other trees. The wood is used for fence posts, insulator pins, treenails, furniture, and archery bows. In fact, many archers consider the wood of the Osage-orange to be the world's finest wood for bows. (The name bodark is from the French bois d'arc mean "bow wood.") Also, a bright yellow dye can be extracted from the wood.
It is the fruit of the Osage-orange that most individuals find intriguing. In the hands of a child, the fruit can become dangerous weapons. They are a nuisance in the home landscape. The "hedge apples" are not an important source of food for wildlife as most birds and animals find the fruit unpalatable. (However, the thorny trees do provide nesting and cover for wildlife.)
The use of the hedge apples for insect control is one of the most enduring pest management home remedies. Placement of hedge apples around the foundation or inside the basement is claimed to provide relief from cockroaches, spiders, boxelder bugs, crickets and other pests.
The use of hedge apples as a pest solution is communicated as a folk tale complete with testimonials about apparent success. However, there is an absence of scientific research and therefore no valid evidence to confirm the claims of effectiveness. Although insect deterrent compounds have been extracted from hedge apples in laboratory studies, these do not provide a logical explanation about why hedge apples would work as claimed. At this time, there is nothing to recommend the use of hedge apples for pest control.
While the Osage-orange is hardy in southern Iowa (USDA Hardiness Zone 5), it is not a suitable tree for the home landscape because of its large fruit and sharp thorns. Attempts have been made by horticulturists to identify and select male, thornless cultivars. Unfortunately, no cultivar has proven to be completely thornless. Until a true thornless cultivar is found, the Osage-orange is probably best suited for wildlife plantings in rural areas.
The milky juice present in the stems and fruit of the Osage-orange may cause irritation to the skin. While the fruit have been suspected of being poisonous to livestock, studies conducted in several states have been negative. However, the fruit may cause death in ruminants by lodging in the esophagus and preventing eructation or release of ruminal gases.
This article originally appeared in the October 10, 1997 issue, p. 143.