COLUMBUS, Ohio – It’s a horrible but beautiful tree. The stunning white blooms of Callery pear trees are showing up everywhere in Ohio and other states right now. But they are invasive and choke out native species. Callery pears have been banned from being planted or sold in Ohio since January 2023.

Callery pear trees were first brought from Asia to North America in the early 1900s, said Stephanie Downs, the Ohio Division of Forestry’s private lands administrator. They were brought over primarily for agricultural use. Plant breeders were looking for a rootstock that they could graft commercial pears onto that would produce edible fruit and be disease resistant. Callery pears looked like the answer and that was fine as long as they were all root grafts.

“Callery pear is unable to self-fertilize. so as long as genetics are all identical, they don’t produce seed,” Downs said. “The problem was when the trees were planted in the landscape and after they were maybe 20, 30 years old, they started noticing the growth form of the trees lends itself to breaking apart in storms.”

The landscape industry wanted to see how they could preserve this tree as a planting stock, Downs said. They started looking at different varieties or cultivars that had better form but still had the good characteristics – they grow in a lot of soils, tolerate a lot of conditions, and have really pretty leaves and flowers, so they started looking at developing cultivars. Bradford pear is a variety of Callery pear.

“The issue with the cultivars was they introduce different genetics, but once you have more than one variety they can pollinate each other and they start to produce seed,” Downs said. “That’s when the good reasons that they brought this tree over started becoming a problem. They grow in almost any soil type, they grow well in a wide range of conditions, and they produce a lot of seed. They started spreading.

“It took a few years for them to produce viable flowers and start cross-pollinating,” she said. “People realized they were cross-pollinating and they started popping up all around. They reduced our native biodiversity, reduced habitat for wildlife, and started causing a lot of other problems.”

The Ohio Department of Agriculture (ODA) began to notice this about 2016, said Ken Reed, ODA’s plant pest control administrator. There is an ODA committee that evaluates different plants. Callery pear came to the forefront in 2018.

“In 2018, the nurseries were given five years to phase out stock,” Reed said. “The five-year period was given because it was a woody plant and nurseries had quite a bit of product in their stores. Our goal is never to cost commerce. So, there was a five-year period for it to phase out and it went into force in January of last year, 2023. This will be the second year for anyone not to be able to sell Callery pear trees.”

ODA did not receive any pushback from nurseries, Reed said. The committee that made the decision has members from universities, nursery representatives, and more. They made the coming ban public knowledge.

“Each one of the inspectors worked with the nurseries in their territories to help them know it was coming and make sure they were phasing out their stock,” Reed said. “The only thing we had was a few box stores, sometimes they ship in product from other states that don’t have the Callery pear quarantine yet. We had three locations (in 2023) we came across and we had them take the trees out of sale and ship them back to the warehouse.”

Homeowners most often notified ODA of the banned trees being offered for sale. That is helpful because ODA inspectors cannot get to every box store when they get a shipment, although they visit as many as possible.

“People knew it was a problem back in the 1970s,” Reed said. “Callery pear grows quickly, has that pretty flower on it, but it becomes invasive. Now it is in road ditches, any unmanaged areas. It chokes out all of the native plants.”

Just cutting the trees down doesn’t help, Downs said. They will re-sprout from the roots and the stump. It takes chemical control, cutting the tree down and using an herbicide on the cut surface to let it soak in and kill the root system.

“Read the labels and make sure you can apply it to your site correctly,” Downs said. “Make sure it is one you can use as a cut-stump treatment. They can still send up root suckers but most of it is spread by seed.

“At this point, we are reliant on the people who own property and who care about the environment,” she said. “Right now, it takes management to restore the native ecosystem. We are trying to limit the impact that they have on our ecosystem to preserve all of the things that we like in our woods.”

The problem is there are so many of the trees and the seeds are spread by birds who eat the fruit, so it takes continual management, Downs said. Getting rid of the trees forever is no longer an option.

“But we can pick the areas that provide all those ecosystem services we’re looking for and protect them, focusing our efforts on those high conservation areas, controlling the Callery pear there and working to keep those areas functioning,” she said.

There are alternatives to Callery pear. Downs said her favorite is Serviceberry. It is a native small tree, has white flowers in the spring and produces a small, edible fruit. Other options are dogwood, Eastern redwood, black gum and hop hornbeam.

Bans similar to Ohio’s will take effect in 2024 in South Carolina and Pennsylvania. North Carolina and Missouri will give residents free native trees if they cut down Callery pear trees on their property.