Botany 155 / Meicenheimer
September 28, 2009
Honeylocust pods Honeylocust bug
Honeylocust Tree - Scientific Name: Gleditsia triancanthos
Native Honeylocust trees are best known for their hazardous thorns and long, flat seedpods. For most uses, the thornless, podless nursery varieties are considered superior. The lacy foliage gives a loose, open shade ideal for yards and shade loving plants. In autumn, the small leaflets filter into the grass as they fall, requiring little raking. Suggested uses for this plant include: shade, street tree, massing, and specimen plant.
“The tree's technical name, Gleditsia triacanthos, comes from the German botanist Gottlieb Gleditsch, and from Greek words for "three-spined" since new thorn growth often branches into threes. Occasionally, individual Honeylocusts produce no spines at all, and scions from these trees have been cultivated and sold commercially to property owners...Other folks have taken advantage of the Honeylocust's stout thorns, including Civil War soldiers who reportedly used them to keep their uniforms together when metal pins were scarce. We assume the troops used the thorns on coats and jackets but not on trousers. Ouch!” 1
Foliage: Deciduous broadleaf tree Height: 30 to 70 feet Spread: 30 to 50 feet Shape: Spreading - Long compound leaves have little leaflets giving the foliage a lacy effect. Plants and flowers grow well beneath it because light filters through the small leaves. The bright green leaves turn yellow in the autumn.
Tree Needs: Zone: 4 to 9 Light: Partial shade to full sun Moisture: Wet, moist, or dry Soil Type: Sandy, loam, or clay pH Range: 4.5 to 7.3
Notes: There are improved thornless, podless varieties. Honey locust is easy to transplant because it withstands a wide range of conditions. Does best in moist soil or with high pH. Prefers full sun. Is very salt tolerant. Historically the honeylocust had no known pests. Recently, the honeylocust bug is a danger.
Care: Spray twice yearly to control webworms. Susceptible to mimosa webworms, leaf hoppers, spider mites, and leaf galls. Webworms are the worst problem and sometimes they will defoliate the trees by August. The honeylocust bug lays eggs in linear clusters under the bark of 2 and 3-year old twigs. The eggs then lie there over the winter. The adult bug appears by late May and early June, and measures 1/8 inch in length. There is one generation per year and the adults usually disappear by mid to late July. The honey locust plant bug causes death to the leaf cells on immature growth, resulting in severe leaf distortion,
dwarfed leaflets and yellow to brown spots often appear. Spraying is the only way to control large infestations because so far, no non-chemical means of honeylocust bug control has been found.
Historical Connection: Another interesting Civil War fact is that in Gettysburg, Pennsylvania, President Abraham Lincoln was near a honeylocust when he gave his famous Gettysburg Address after the Civil War. The tree was a witness to many of the horrors of the battle. But, sadly, on August 10, 2008, the tree fell.
“Standing just 150 feet from the platform on which President Lincoln delivered his most famous speech, one of the few remaining "witness trees" to the Battle of Gettysburg has been severely damaged by a storm, National Park Service officials said. A park historian knows of only three other witness trees that stand in the heart of the battlefield. The huge honey locust tree on Cemetery Hill fell Thursday evening. ‘The top of it is totally broken off, and [the storm] severely damaged 70 to 80 percent of the tree,’ Gettysburg National Military Park spokeswoman Jo
Sanders said. ‘That means there's not a whole lot left of it. But it didn't kill the tree.’ The tree, which stood on the right side of the Union lines, "was there as a silent witness -- to the battle, to the aftermath, to the burials, to the dedication of the cemetery," park historian John Heiser said. ‘I have no doubt that Union soldiers sat under it for all three days of the battle,’ he said. Park maintenance officials will decide what to do with the remains of the tree.”2 It is believed it will survive, since the Honey Locust is a very strong and resilient tree. Some of the wood from the fallen section will be donated to the Gettysburg Historical Society. They hope to sell it in some form to raise funds for the care of the Gettysburg Battle site.
Sources: http://www.treehelp.com/trees/locust/locust-types-honey.asp. retrieved 09/07/2009.
http://ipm.illinois.edu/landturf/insects/honeylocust_plant_bug/index.html. retrieved 09/14/2009.
http://www.northern.edu/natsource/TREESA1/Honeyl1.htm. retrieved 09/15/2009.
http://www.tree-pictures.com/honeylocust_tree_pictures.html. retrieved 09/07/2009.
http://www.friendsofgettysburg.org/UpdateonGettysburgsWitnessTree.htm retrieved on
The Honey Locust tree in the National Cemetery
in the center of the photo still has branches
and leaves, but much of its main trunk
was blown off in a recent storm. (8/10/2008)
(Photo courtesy of Katie Lawhon,