What started as an attractive addition to suburban Indiana landscapes has turned into a threat to Hoosier forests.
For years, ornamental pear trees, most commonly known as Bradford pears, have been a popular landscaping tree. They were planted because the trees grew quickly and had attractive white blossoms. But the original variety was weak and prone to splitting, especially during storms. So foresters developed stronger cultivars.
Over time, these newer varieties cross-pollinated, allowing them to rapidly spread out of the subdivisions and into Indiana’s forests. As a result, they are crowding out native Indiana trees. For that reason, the Indiana Department of Natural Resources encourages homeowners and landscapers to avoid planting such trees and to replace them when possible.
Cultivated forms of this invasive species are most accurately known as Pyrus calleryana or Callery pear tree. Commonly available ornamental pear cultivars, all of which are invasive and should be avoided, include Bradford, New Bradford, Cleveland select, autumn blaze, Aristocrat, capitol, Chanticleer, and dozens more.
Evidence of the trees’ rapid spread is easy to see. In Franklin, for example, motorists on U.S. 31 at Youngs Creek can see pear trees planted in suburban lots on the west side of the highway. But runaway trees are visible near Greenlawn Cemetery on the east side of the road and at the edge of a drainage ditch on the west side at the edge of Blue Heron Park.
These stray trees likely were planted when birds ate the small fruits and then deposited the seeds elsewhere. That means there’s no way to keep these invaders restrained. They must be cut down and replaced with native species that are best suited for our region.
If you are looking for an alternative flowering tree for Indiana, serviceberry trees, which have similar white blooms in the spring and fruits that attract wildlife, are one option. Eastern redbud, which grows quickly, with eye-catching lavender flowers in the spring, is another option.
Bradford pear varieties are still commonly sold at large home centers even though they are a demonstrated detriment to Hoosier forests. So don’t buy them. Plant native species instead.
Another menace to our forests that remains readily available is burning bush. This deciduous shrub is known for its bright red fall foliage. While strikingly attractive, it can be easily spread to forest areas, where it can form dense thickets that displace native plants.
The detrimental nature of burning bush has been known for decades, yet stores continue to sell it to homeowners who are unaware of its impact on the forest ecosystem. Most people see a few good-looking, often well-pruned, burning bush shrubs in a front yard and wonder where the invasion is. What’s all the fuss about? But once we can all see it, it is way too late.
There are several good, native alternatives to burning bush. Chokeberry, for example, has white flowers in the spring, beautiful fall foliage color and berries in late summer that last into winter, that is, if the birds don’t eat them all first. It is hardy and adaptable to many conditions.
Dogwood and sumac also are good alternatives.
Still another readily available invasive plant is wintercreeper, commonly sold as a ground cover. This plant competes with native plants by depleting soil moisture and nutrients, blocking sunlight and forming a dense mat that impedes growth of seedlings of native species. Several native alternatives are readily available.
Preventing the spread of invasive species requires effort from a variety of stakeholders, including government and retail businesses. But most of all, it starts with individual homeowners who decide to remove invasive species from their yards and replace them with plants that nature meant to be grown there in the first place.
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To learn more about native plants that are great for landscaping, visit the Indiana Native Plant and Wildflower Society page at inpaws.org/landscaping
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