By Molly Day
All the Dirt on Gardening
Osage Orange trees are advertised in plant catalogs as small to mid-sized, meaning they become 30 to 50 feet tall, with a 40-foot-wide crown at maturity.
It is said that in early American history, these thorny trees were planted along property lines as fences, keeping animals in and strangers out, and making prairie settlement possible. Osage Orange fence posts took root across the prairie and made thickets in ravines and farmsteads.
The many names that Maclura pomifera is known by include: Orange wood, bois-d’arc, bodark, bowwood, hedge-apple, mockorange, and live barbed wire.
The wood of this mulberry family member is not only strong enough to make hunting bows, it is the only tree that produces orange wood. The Lewis and Clark expedition noted finding it in St. Louis in 1804. Early settlers used the root bark to make a yellow dye.
Native to Arkansas, Oklahoma and eastern Texas, Maclura pomifera are now found in zones 4 to 9, from New England to southern Colorado. Some have naturalized rural areas in the Pacific Northwest (http://plants.usda.gov).
In their native range, small Osage Orange groves were found in bottom land where the soil was called bodark swamp, a common name for bois-d’arc. Usually they were in prairie, growing with oak, ash and mulberry. The largest specimens grew close to the Red River.
A 200-year-old Osage Orange tree, 60 feet tall and 90 feet wide, is listed in the National Register of Big Trees (www.americanforests.org).
In the spring, small green flowers are pollinated by wind and insects and the result is large green 4- to 6-inch fruit that is used in crafts and as insect repellent. Homeowners surround their home foundation with the fruit to repel insects.
This time of year, the ground under Osage Orange trees is littered with those brain-looking fruits. When they fall and bruise a milky juice comes out, blackening a spot. One writer said that being around an Osage Orange tree in the autumn is like experiencing falling broccoli.
When the fruit breaks open, livestock, birds and wild animals such as squirrels eat the fruit and spread the seed. Scientists say that 11,000 years ago the large fruit was eaten by mammoths, mastadons, giant sloths and glyptodonts.
Osage Orange does not produce useful wood for timber, pulp or utility poles, but despite its shortcomings it has been planted more than any other tree species in North America www.na.fs.fed.us).
The wood, bark and roots contain valuable extracts for food processing, fungicide, pesticides and dye-making. The heartwood is decay-resistant, disease-resistant and immune to termites. The branches were used by the Osage Indians to make clubs and bows. Today millions of Osage Orange fence posts are sold every year; and slices of the wood are used as garden step stones that take decades to disintegrate.
The trees add valuable shade and texture to the landscape with yellow fall color. Osage Orange trees are still planted all over the country and pruned as hedges. The branches that grow in full sun have thick, 1-inch-long sharp thorns. Twigs in the shaded areas of the tree are thorn-less, but the shade will eventually kill them.
Maclura pomifera grow and look their best in moist gardens and near creeks and ditches, but they can tolerate a year of drought because at maturity their roots spread 15 feet out and 8 feet deep. They are also resistant to deer, heat, road salt and air pollution over their normal 75-year lifespan.
Male, mostly thorn-less and fruitless, varieties include Witchita and Whiteshield. All varieties are cold hardy to zone 5. One source is Forest Farm (www.forestfarm.com).
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