ENVIRONMENT

Bradford pear trees are highly invasive. This is why they aren't banned in Indiana.

London Gibson
Indianapolis Star

Invasive plants are wreaking havoc on Indiana's ecosystems. 

It's why last year the state put the Terrestrial Plants Rule into effect, banning 44 species of them from the landscaping trade. But experts say there were a few glaring plants left off the list.

Most notably? The Bradford pear tree.  

This plant, favored by landscapers for its beautiful white blooms and stately appearance, is one of Indiana's most criminal invasive species.

Bradford pear trees, also called Callery pears, bloom earlier in the year, giving them an advantage over native species and allowing them to take their resources for its own. The trees have become so ubiquitous in Indiana that in some places you can find entire fields of them.

But while they are bad for the environment, they're also economically valuable for growers in the state. Very valuable. An analysis done in recent years found the tree earned nursery owners millions of dollars each year. 

That's why they didn't make it on the terrestrial plant rule.

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The Indiana Invasive Species Council, the group that decides which species to add to the ban, is prohibited from adding any plants that could cause significant economic harm to nurseries and small businesses. As such, a statewide effort is under way to educate consumers about the Bradford pear: If they stop buying, the council can finally add the tree to the list and cut Bradford pears out of the landscape trade for good. 

"We're educating the general public and nurseries about how invasive they are," said Megan Abraham, state entomologist with the Indiana Department of Natural Resources and member of the Indiana Invasive Species Council. "That comes with a lot of public outreach."

Callery pear trees spread across the landscape. These trees are highly invasive, but were left off of the list formed by the Terrestrial Plants Rule, a decision that some in the environmental community opposed.

The effort seems to be working.

In a more recent analysis of the tree's sales around the state, it was found to bring in just under half a million dollars, a substantial decrease. There's not a set dollar amount that the council is looking for before adding the tree to the next list of banned plants, but the council is in the process of reviewing the tree's standings, Abraham said.

Even so, it's a lengthy process and it'll likely be a few years before any changes to the terrestrial plants rule are made, she said. In the meantime, they're ramping up education.  

And although the drop in Bradford pear sales may be good news, there's still quite a bit of work to do in managing existing invasions. 

"We're really focused on educating so that people don't keep planting invasive things, but we have our work cut out for us," said Claire Lane, an urban conservationist with Hamilton County's Soil and Water Conservation District. "And there's already so much out there."

Meadows full of Bradford pear trees

Research indicates that the landscaping trade is responsible for just over 80% of invasive species growing in Indiana. 

And the Bradford pear, with its beautiful springtime white flowers and brilliant fall foliage, is a favorite among Hoosiers. 

Those flowers are part of the problem. They bring with them small fruits, which birds eat, and fly and deposit the seeds elsewhere. Because Bradford pear trees bloom so much earlier in the year than native trees, they drop their seeds when there aren't native competitors. Then, they take over. 

"I've seen entire meadows transformed into a monoculture of Bradford pears," said Ethan Olson, director of native landscapes at local nonprofit Keep Indianapolis Beautiful. 

A Bradford pear tree, a popular cultivar of Callery pear, is shown in blossom.

In the long term this shakes up Indiana's ecosystems, said Heather Reynolds, a biology professor at Indiana University and member of the Indiana Invasive Species Council. When the tree chokes out native plants, those plants can't support native insects and pollinators. Those insects, in turn, can't support the wildlife that eats them, and the impacts snowball from there. 

"Loss of biodiversity has implications all the way up the food chain," Reynolds said. "If you plant a monoculture of Bradford pear, you're ultimately destroying the habitat and food sources for the bird species you may love."

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Once a settlement of invasive plants sets in, they're expensive to get rid of. The process can require clearing plants out by hand, chemicals or prescribed burns. Some invasive plants need to be pulled up by the root, and other may require year-after-year management, Abraham said.  

Overall, it costs upwards of $100 an acre for forest managers to take care of, she said. 

Statewide, it cost an estimated $5.85 million to manage invasive plants in 2012. In 2018 alone, Carmel Clay Parks and Recreation spent more than $140,000. 

"There's a whole lot more that needs to be spent to eradicate these invasive species," said Kyle Daniel, nursery and landscape outreach specialist at Purdue University. "Some of them can take over the entire ecosystem."

How the council picks which plants to strike out

The Indiana Invasive Species council, made up of 11 members representing different backgrounds, ranks invasive species by the level of invasiveness and then puts the most highly invasive species through a fiscal analysis to understand its economic impact on the state. It's a lengthy process, Abraham said, that takes a few years from start to finish. 

The council selected the 44 species that were banned by the Terrestrial Plants Rule, which went into effect last year. The rule banned the ubiquitous Japanese barberry and and wintercreeper.

Rick Haggard, executive director of the Indiana Nursery and Landscape Association and member of the invasive species council, said nurseries play a big role in the Bradford's success.

That said, Haggard points out that nursery owners are faced with the choice of selling that plant and earning a substantial portion of their income on it, or not selling it and the customer just goes next door to a big box store for it. For lasting change to happen, he said, there needs to be an adjustment on the part of the consumer as well.

"It's just making people aware of other species and other plants that can be utilized as replacements," Haggard said. "I do think it's just a matter of time, it's not going to happen overnight."

Education efforts

Daniel, who works for the INLA educating nursery owners and industry professional, said he's already noticing change happen. He said many, if not most, Indiana nurseries have either stopped selling or greatly reduced sales of the Bradford pear tree, also noting that big box stores are a different story.

"I think it's a combination of, nurseries want to do the responsible thing, but also the demand," Daniels said. "If there's not demand, they're not going to grow it. And so by attacking both sides, that's what's reduced the need for that plant."

Keep Indianapolis Beautiful Director of Native Landscapes Ethan Olson starts to plant some native Indiana plant seeds Tuesday, March 16, 2021 at the KIB nursery in Indianapolis. The plants will be sold to the public starting in May.

The Invasive Species Council is in the process of reviewing the Bradford pear now for the next iteration of the Terrestrial Plants Rule, but they're also trying to be careful given how small businesses have been affected financially by the COVID-19 pandemic. This means they may be even more conservative in evaluating the economic impact moving forward. 

Daniel, however, feels confident that the pear tree will be included in the next ban.

"Whenever we're looking for the next round," he said, "Callery pear would almost certainly be on there."

What you can do

Aside from avoiding planting invasive plants in your own backyard, there are several ways that you can help the Hoosiers working to manage invasive species across the state.

Try volunteering at your local Cooperative Invasive Species Management Area, said Lane, who helps to lead Hamilton County's CISMA. These are groups of volunteers around the state that work together to remove invasive species in natural area. 

Reporting invasive populations in natural habitats will also help experts track them down, said Olson. If you see a Bradford pear population in the wild, he said, let your local CISMA know. 

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Invasive plants choke out habitats for native plants that act as crucial habitats or food for pollinators such as bees and butterflies. To help combat nationwide pollinator population declines, try planting native flowers and trees in your hard this spring. 

Olson points out that many of the native alternatives are also sturdier than Bradford pear trees, which are famously fragile in the face of strong winds and storms. This may also be an opportunity to support local landscaping businesses, Abraham adds.

Here are some native and non-invasive alternatives to Bradford pear trees, according to experts:

  • Dogwood tree: Like Bradford pear trees, Dogwoods are covered in white blossoms in the springtime.
  • Eastern Redbud trees: Redbud trees are known for their flashy pink flowers in the springtime, and could be a non-invasive option for those looking for springtime blooms.  
  • Serviceberry tree: As an added plus to Serviceberry trees' white flowers, their berries are also delicious, Olson said. 
  • Cherry tree: Cherry trees native to Indiana provide fruit and food for wildlife. 
  • Oaks and maple trees: Native oaks and maples can support hundreds of types of wildlife and insect species, Olson said, far more than some other ornamental trees can. 

Contact IndyStar reporter London Gibson at 317-419-1912 or lbgibson@gannett.com. Follow her on Twitter @londongibson

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IndyStar's environmental reporting project is made possible through the generous support of the nonprofit Nina Mason Pulliam Charitable Trust.