Monday, March 21, 2016

Pretty White-blossomed Pear Tree Used in Landscaping has an Unwanted, Invasive Side

Contact: Patrick Byers, horticulture specialist
Headquartered in Greene County
Tel: (417) 881-8909

Written by David L. Burton

SPRINGFIELD, Mo. – With angelic white blossoms that transform the spring landscape, flamboyant foliage in fall and abilities to tolerate air pollution and resist disease, the Bradford pear became a favorite choice in commercial and home landscapes.

However, this beauty has a nightmarish side according to Patrick Byers, horticulture specialist with University of Missouri Extension.

“People ask, ‘What is the beautiful tree that is blooming along the interstate or along Hwy. 60’?” said Patrick Byers, horticulture specialist with MU Extension. “In warmer southern states, like Arkansas and southern Missouri, the tree is now considered an invasive species.”

The tree, one of several cultivars of the Callery pear, was brought to the West from China in the late 1800s as a small ornamental. Over the years, more cultivars of the pear were developed with an eye toward strengthening its weak branch structure.

The breeding also moved the pear away from being a non-fruiting tree that was cloned for sale in the trade, to being one that produced lots of fruit and lots of seed.

The tree can spread both by seeds and vegetatively through sprouts from the base. The tree’s white blossoms are now almost ubiquitous in any place where the sun shines – parks, highway rights of way, vacant lots, even areas under partially open forest canopies.

The same toughness that made it such a good choice in heavily trafficked landscapes, also makes the pear an aggressive spreader that can quickly crowd out native species. Once the darling of the landscaping trade, this tree has escaped cultivation and is considered an invasive species.

“This widespread invasion creates problems for farmers, ranchers, or anyone managing acreage,” Byers said. “The invasive plants are very difficult to control. Mowing them, if you don't pick up a thorn that will blow your tires, only creates more sprouts from the base.”

Girdling of mature trees can be an effective control. Herbicides can also be effective.

The Missouri Department of Conversation has additional information on this problem online at http://mdc.mo.gov/sites/default/files/resources/2012/05/callerypearinvasive.pdf.

MU Extension programs focus on the high-priority needs of Missourians to improve lives, communities and economies by providing relevant, responsive and reliable educational solutions. Each county extension center, with oversight by locally elected and appointed citizens, is your local link to practical education on almost anything. More information on this topic is available online at http://extension.missouri.edu.
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