Bradford bristles: Once popular, now invasive

How Bradford brushes became a problem

Bradford pears (also known as Callery pears) were once a common choice for landscapers and homeowners. They are beautiful trees for spring flowering, and their foliage turns a vibrant red in fall – which sounds great, right? But in recent decades, experts have flagged these trees for being invasive to our environment both in Iowa and the broader Midwest.

“They weren’t on our radar in the early 2000s as a problem,” says Jan Thompson, the Morrill Professor in the Department of Ecology and Natural Resource Management at Iowa State University.

Bradford brushes cross-pollinated and spread quickly—from yards to parking lots—causing ecosystem imbalances. Thompson says the trees were ALLEGED to be sterile and fruitless, but they are not – they actually produce seeds that look like miniature pears.

Minnesota Department of Agriculture

After the first frost, the seed coat is softened and the fruit becomes a popular snack for birds, which is then spread to another location through faeces. Fruits spread by carnivores like these contribute greatly to the growth of invasive plants. Having said that, it is also worth noting that birds also spread the seeds of other plants that we find pleasant.

Bradford bristlecones are also “light-wooded,” meaning they are prone to breaking down during heavy storms. During the 2020 straight, many Bradford pear trees were destroyed by high winds.

And if that’s not enough, the spring flowers they produce? I smell—very bad.

How to help

According to Thompson, there is only one surefire way to mitigate the problem.

“We must remove the source … the source is the seed, and the only way to remove the seed is to remove the seed-bearing plant.”

Which means if you planted the tree, you should cut it down. But if you’ve planted Bradford pears in the past, don’t feel bad! Even the experts didn’t know these plants would become such a problem.

“We use a lot of non-native plants in our landscapes, and generally most of them are good to use, and that’s what we thought about Callery pears,” Thompson said.

If you’re looking for native alternatives, Thompson suggests mini crab apples, wild plums, redbuds, elderberries and berries.

Jan Thompson made her comments about I’m talking about Iowa.