Voices: It’s time for Utah to phase out this stinky, dangerous and overplanted tree

It’s that time of year again: crisp mornings followed by warm afternoons; the sounds of birds as they return from migration, pairing up and building nests; the sights of crocuses and forsythia in their glorious golds and purples; and the smell of … sniff … well … what is that smell exactly?

Everyone has a different analogy for that smell, and none of them are evocative of anything good. But it certainly wouldn’t be springtime in Utah without the controversial scent of Callery pear blossoms wafting through the air.

The Callery pear (Pyrus calleryana), often called the Bradford pear, is about as divisive as a tree gets. As a lead horticulturist at Conservation Garden Park, I’ve seen this tree be loved and vilified in ways few plants seem to have achieved.

On one hand, this tree has a lot going for it: It grows very fast, providing shade sooner than other trees. It grows quickly, making it inexpensive. Its beautiful autumn display of reds, yellows and purples rivals any tree in cultivation. But where this tree really shines is its impressive spring display of brilliant white flowers. The flowers then fall to the ground creating a white carpet that contrasts nicely with any colorful bulbs planted beneath.

However, after decades of being the darling of landscapers and homeowner associations across the Wasatch Front, it’s now clear that the Callery pear has some very serious drawbacks. Its rapid growth leaves its wood weak. Combine that with branches that attach at narrow angles and you have a large, brittle tree that breaks easily — even in moderate wind or snow loads. And while this plant was once thought to be sterile, it now produces fruit, the seeds of which are easily passed through birds and grow readily in spots that are not suitable for large trees. And that amazing spring floral show is paired with a smell that many people describe as similar to vomit or rotting fish.

Possibly the worst outcome of the popularity of the Callery pear is that it is wildly overplanted, meaning it has pushed out better adapted or native trees in our landscapes causing the diversity of our urban forests to dwindle. Callery pear trees simply became too easy and inexpensive to pass up despite its flaws. This overplanting of a single species causes another significant problem: Ornamental pear trees are very susceptible to fire blight, a bacterial infection spread from insects through prolific blooms, wind, rain or even pruning tools. Once one tree gets fire blight, it becomes easy to transmit to nearby pear trees and other plants in the rose family, such as apples, crabapples and roses.

As more professionals have raised the alarms about the problems with this tree’s environmental impacts, the Callery pear tree has found itself being placed on many states’ noxious weed lists and has been banned in others. South Carolina even has placed a bounty on them, offering a native tree for proof of its removal.

Here in Utah, a quick look and sniff around reveals the Callery pear tree is still popular, but sales are declining — which means the message about the significant issues with this tree is spreading.

It’s time to phase this tree out in favor of better adapted or native trees. However, we need to replace it with more than a single type of tree and use more types and varieties of trees to diversify our urban forests.

Let us not lose sight of the human role in overplanting a single type of tree. People have fallen into this trap many times in its search for the one perfect tree; overplanting elms led to Dutch elm disease destroying large swaths of landscape trees. The primary trees replacing those elms were ash trees, which were soon devastated by the emerald ash borer, a pest that has almost made its way here from Colorado. Overplanting Callery pears has not only led to unpleasant springtime odor, but to the rise of disease and city streets lined with dying trees just when those trees should be reaching their mature size. These problems weren’t about the trees themselves, but an overreliance on a small number of tree species; a problem we should make the choice to not repeat.

There are several fantastic trees available for Utahns to choose from. Below are some suggestions for high quality trees that can take the place of those ubiquitous flowering pears, many of which you can find growing at Conservation Garden Park.

Trees with a similar look to Bradford pears:

Other quality trees, adapted for the northern Utah landscape:

Mike Lorenc is a lead horticulturist at Conservation Garden Park.

The Salt Lake Tribune is committed to creating a space where Utahns can share ideas, perspectives and solutions that move our state forward. We rely on your insight to do this. Find out how to share your opinion here, and email us at voices@sltrib.com.