Nine-Minute Naturalist: The Callery Challenge
Filed under: Nine-Minute Naturalist
The Callery Challenge
by Josh Palumbo, Forest Management Coordinator
I welcome you to The Nature Foundation at Wintergreen’s attempt to bring some nature and knowledge into your home. The Nine Minute Naturalist borrows from NPR’s lovely 90-Second Naturalist podcast. Since we all have a bit more time on our hands, the goal is to take something that is happening out in our environment and stimulate your brain for roughly nine minutes. Don’t let something as “minor” as a quarantine to keep you from learning. I hope you enjoy!
The balmy winter of 2022/23 was not kind to ski enthusiasts and snow lovers alike. The unseasonal warmth made snow fade from our thoughts and turned our attention to the early blooms of spring. A drive-up rt. 151 illuminated the early onslaught of spring with lively yellow and white blooms throughout the landscape. While color in February is a lovely benefit to warm winters, a general rule of thumb is that if a plant is willing to bloom in February, it is most likely non-native. Along every hedgerow or field edge appears trees draped in white blooms identifying itself as an unwelcomed visitor. This Nine-Minute Naturalist will examine the ever-abundant Callery pear taking over the margins of central Virginia.
In the early 1900’s, cultivated pears in the western United States was suffering from fire blight. Scientists journeyed across the globe to China in search of blight resistant pear species. One of the species brought back was Pyrus calleryana or Callery pear. It was introduced to Medford, Oregon and Glenn Dale Maryland, where I was first introduced to this tree. One of my first internships was working at a woody plant research center where the initial Callery pear cultivar, Bradford pear, was created. Bradford pears were created to be sterile but in fact, cross pollinate with other pears reproducing quite vigorously. The evidence of this “sterile” cultivar is seen and felt at this research center I was employed. The offspring of the Bradford pear cultivar are armed with long, strong thorns able to pierce an ATV tire, as I did on numerous occasions that summer.
Thorns alone are not enough to earn my condemnation. The primary evidence to condemn this plant is their contribution to their local ecosystem. When not in fruit, this aggressive invader constitutes a food “desert.” Most woody plants feed hosts of insects and caterpillars thus providing the staple food for birds, especially bird hatchlings. Songbirds require thousands of caterpillars just to raise a clutch of eggs. The list of insects and caterpillars that feed on Callery pear is close to zero which means every tree taking up space on field edges or in yards offers very little benefit to most of the wildlife. Another attribute it shares with most invasive plants is the difficulty of removal. Physical removal or killing it back with fire only results in an aggressive sprouting campaign by the tree. Where you once had one tree, you will have four if you don’t follow up physical removal with chemical application to kill the root system.
The best way to help stop the spread is to not plant them in the first place or remove any Bradford pears on your property. Avoiding this plant not only aids in controlling the spread but it also saves yourself hassle. While the tree has beautiful spring blooms and a thick canopy of waxy green leaves, it has a nasty tendency to break at the first hint of snow, ice or wind. This short-lived tree has a steep V shaped branching structure that leads to a constant break up of the canopy once it reaches maturity. South Carolina has gone as far as offering a Bradford pear bounty program. A removal of a landscape Bradford pear entitles the proactive homeowner to one replacement tree.
As you drive around this burgeoning spring, do not be fooled by the lovely white blooms filling in the countryside. Those are the evidence of an army in the process of invasion. Stop this trend by removing Bradford pears and seeking lovely native replacements such as downy serviceberry, which is known to host 119 species of native caterpillars, or the lovely flowering dogwood. Seek to have a thriving ecosystem not a food “desert.”