Killer pears attacked by Master Gardener

I would like to weigh-in on the debate about the removal of bradford pears in the center of the Village of Yellow Springs.  I appreciate having this blog as a public forum to disperse some information.  In 1982 the bradford pear, Pyrus calleryana Dcne, was voted the second most popular tree by the National Landscape Association. But since then it has moved to the top of the worst tree list in many states including Ohio.  What happened?

This cultivar of bradford pear came from China and was planted as rootstock for cultivated pears in the early 1900’s.  Since it was not self-pollinating, it produced no fruit.  However, when it was planted near other pear varieties, it eventually cross-pollinated to become a much different tree by producing fruits, thorns, and seeds and by growing taller.  Its spread into natural areas began in Maryland and Pennsylvannia where these hybrids produced small fruits that birds, especially starlings, loved.  The seeds spread by birds sprouted, grew, and quickly began to knock out stands of dogwoods and redbuds.  Instead of growing about 20 feet tall as they did when they didn’t produce fruit, the fertile bradford pear grows up to 60 feet tall and spreads to 30 feet.  The tree lives about 25 years if it survives without splitting in a wind storm which many do.  We are in trouble.

This tree is being declared invasive in southern, eastern, and midwestern states including Ohio. Kathy Smith, Ohio State University Extension forestry specialist in the School of Environment and Natural Resources, said at last year’s the Farm Science Review, "You drive into Columbus during the spring when the pears are blooming and they appear to be everywhere.  Once established, they dominate a site just as most of the invasive species do. There are places in Ohio where there are groves of pear so thick you can't walk through them and each of those plants has the ability to reproduce."

A Southwest Ohio Ohio Department of Natural Resources regional forester describes the trees, “They are colonizing waste areas and open fields, and are very tough to control.  Most of you are eyeing all of the greening bush honeysuckle this time of year.  Look carefully and you will see that callery pear will pop up among the honeysuckle.  Yes, callery pear is out competing exotic bush honeysuckle!”  In addition, the ODNR invasive plant webpage listed it as one of its Invasive Weed of the Month. 

In Yellow Springs, many volunteers have removed invasive garlic mustard and honeysuckle from the Glen. Do we want to add thorny bradford pears to this list? Nick Boutis, Director of the Glen Helen Ecology Institute, is already seeing them in the Glen.  For a change, we have a chance to remove the seed source before the trees overwhelm the Glen and prevent the oaks, maples, and other natives from growing.

In addition to their invasiveness, our village pears are in poor shape, not healthy as some critics claim.  They naturally want to be big and spreading, but to avoid hitting buildings and overhead wires, they have necessarily been pruned into unnatural shapes.  Their roots are not compact enough to fit in the small tree wells so they are heaving the sidewalk to find water and nourishment.  These are not healthy trees.  In addition, the bradford pears are notorious for their tendency to split in storms. We are fortunate that one hasn’t already come down on a car, building, or pedestrian.

In other words, bradford pears are no longer appropriate street trees. For the safety of people doing business in town, for the health of the Glen and other natural areas, and for the enjoyment of seeing trees that look like trees, it’s time to replace the pears when sidewalks are installed and wires buried. I’m confident that a committee of experts who know street trees will choose one or more suitable species that will once again provide us with welcome shade and ample branches for artists to decorate. 

Macy Reynolds

Greene County Master Gardener

Ohio Master Gardener Tree Specialist

YS Tree Committee Secretary