Pennsylvania begins phasing out sales of Bradford pear tree
Courtesy of Mason Heberling
Courtesy of Mason Heberling
Leaves from a young Bradford pear tree planted at the carriage entrance to the Carnegie Museum of Natural History were cut and documented by the museum鈥檚 herbarium department.
Each spring, Bradford pear trees add a pop of color to the Carnegie Museum of Natural History鈥檚 entrance. Planting of the Callery pear tree was banned inside Pittsburgh鈥檚 city limits in 2015. (Photo courtesy of Mason Heberling)
Courtey of James H. Miller
Courtey of James H. Miller
Courtey of James H. Miller
Callery pear trees are known for their pretty white blooms.
Courtesy of David J. Moorhead
Courtesy of David J. Moorhead
Courtesy of David J. Moorhead
Callery pear trees spread like weeds, especially in bright fields, across the commonwealth. Planting of the trees is being phased out because Callery pears choke out native species.
Katherine Mansfield
Katherine Mansfield
Katherine Mansfield Bradford pear trees line the streets of downtown Washington. The tree was recently added to Pennsylvania鈥檚 Controlled Plants and Noxious Weeds List and will be phased out over the next two years.
Courtesy of Dr. Ben Dolan
Courtesy of Dr. Ben Dolan
Callery pear trees are often part of public landscaping and, despite a pungent odor when they bloom, are admired for their bright white flowers. These Callery pears line a quiet street in Findlay, Ohio.
The Pennsylvania Department of Agriculture recently announced the addition of Callery pear to its Controlled and Noxious Weed List, along with a plan to phase out the sale and planting of America鈥檚 darling by 2024.
鈥淚t鈥檚 popular as a street tree. A lot of people line their driveways with them; they are in a lot of public places,鈥� said Scott Weaver, fourth-generation owner of Iannetti鈥檚 Garden Center in Burgettstown. 鈥淚t is a very popular tree. It is a very attractive tree. People really like them.鈥�
The public has adored Callery pear trees (also called the Bradford pear tree in Pennsylvania) since the species鈥� introduction to the United States more than a century ago.
During the early 1960s, the National Arbor Day Foundation鈥檚 celebrations included the distribution of the tree nationwide, and as part of Lady Bird Johnson鈥檚 beautification program, she promoted the Callery pear tree.
Callery pear was lauded in the New York Times for its supposed immunity to fire blight, a contagious plant disease. It was easy to grow and its flowers 鈥� Dr. Jason Kilgore, associate professor of biology at Washington & Jefferson College, describes them as 鈥渟howy, white, prolific flowers鈥� 鈥� were unmatched in beauty.
The Callery pear鈥檚 roots were grafted onto other fruit trees to help them grow; the tree was cloned, and varieties of Callery pear lined the streets of grand cities, including Pittsburgh.
The Callery pear was everywhere.
鈥淓veryone thought it was great,鈥� said Mason Heberling, assistant curator of botany at the Carnegie Museum of Natural History. 鈥淚t鈥檚 actually quite common. You don鈥檛 have to go very far to find it. I鈥檝e seen a lot in old fields, abandoned fields 鈥� or cut-down forest along the highway. Callery pear is definitely a concern.鈥�
The Callery pear has been on scientists鈥� radars for the past couple of decades.
鈥淢ost invasive species take time to become invasive,鈥� said Kilgore, who also founded and curates W&J鈥檚 campus arboretum. 鈥淐allery pear escaped from cultivation where we intended to plant it in the mid-60s, in Maryland. We鈥檝e known since the 鈥�60s that the plant can escape, but the plant didn鈥檛 become noticed as an invasive plant until the early 鈥�80s. Since then, the plant鈥檚 population exploded across eastern North America.鈥�
And in the last 10 years, said Shannon Powers, press secretary of the DOA, Pennsylvania has taken note of the species鈥� spread.
鈥淛ust over the last decade, it鈥檚 become more and more readily apparent it鈥檚 naturalizing, it鈥檚 spreading,鈥� she said. 鈥淚t鈥檚 a lovely tree. It鈥檚 beautiful when it blooms, but it smells horrible. For some people, it鈥檚 an allergen. That in itself is not reason to ban a sale of a tree. The reason to ban the sale of a tree is when it鈥檚 a danger to our environment, our ecology and human health.鈥�
The Callery pear tree and its derivatives, including the Bradford, have begun impacting the growth of native species.
鈥淚t spreads without human intervention,鈥� said Heberling. 鈥淚t鈥檚 not from our area, so it鈥檚 competing with our native vegetation and impacting the natural ecological cycle. Other things won鈥檛 grow under the Callery pear; that鈥檚 why it鈥檚 problematic.鈥�
Another issue with the Callery pear: it supports non-native species, including the European starling, an invasive bird that works with the Callery pear tree, said Kilgore, whose research includes northeastern North American forests. The two species support each other in their spread across the northern part of the continent.
Adding a species to Pennsylvania鈥檚 Controlled Plant and Noxious Weed list is a big deal. Before fall of 2021, just 39 species had made the list, which has been around since 1862.
鈥淚t鈥檚 a legal procedure,鈥� said Powers. 鈥淭here鈥檚 a deliberation that happens over a period of time. It鈥檚 not just a decision that鈥檚 made and boom, it鈥檚 banned. It鈥檚 tied to regulations.鈥�
Before it winds up on the list, a plant is voted on and must be approved by the Controlled Plant and Noxious Weed Committee. The species is published to the state鈥檚 bulletin and, 60 days after publication, it is formally added to the noxious weeds list.
The Callery pear was added in November.
鈥淚t鈥檚 very unusual to ban a plant that鈥檚 popularly available in nurseries,鈥� said Powers.
Powers said even more unusual is that the Callery pear tree is not the only species recently added to the noxious weed list.
鈥淎 couple months ago, we banned Japanese barberry. It鈥檚 a shrub; it鈥檚 very pretty, it鈥檚 prolific. But it is thorny, so it鈥檚 resistant to deer. It spreads, it harbors ticks, it takes over the understory in the forest,鈥� she said. 鈥淚t destroys habitat.鈥�
Because both the Bradford pear and Japanese barberry are sold commercially, the state will phase out the two species over the next couple of years 鈥渢o allow nurseries and landscapers to replace their stock,鈥� Powers said.
The sale ban of Bradford pear trees goes into effect Feb. 9.
In February 2023, the DOA will issue a letter of warning to anyone still selling the Bradford pear tree. The following February, anyone with Callery pear trees remaining in their inventory will be mailed a destruction order.
鈥淭hat鈥檚 a big deal,鈥� said Heberling. 鈥淚t just brings a bit of awareness. That state botanists and state legislatures are saying that this plant is a troubling plant and therefore would encourage people to remove any Callery pears they have 鈥� this does make it more in the public consciousness.鈥�
The state already announced exemptions to seedless varieties of Callery pear will be granted, after research confirms those varieties are sterile and won鈥檛 pose harm to the environment.
But Heberling and Kilgore agree the best thing for the environment is planting more native species.
鈥淚 always encourage people to consider native alternatives: red bud, native dogwood, small trees like blackhaw, wild plum, chokecherry and hawthorn,鈥� said Kilgore. 鈥�(Those) give a lot of the similar kinds of vibrant, prolific flowers that we would see in Callery pear, that people like. Not only should they be removing, but they should be replacing with native alternatives.鈥�