N.Y. Times op-ed makes case for less tree pollen

(Karen Barbour, nytimes.com)

An editorial published Monday in The New York Times makes the case for planting fewer pollen-producing street trees.

The writer notes that arborists and landscapers like to plant male trees and shrubs because they don’t produce seeds or pods, overlooking the fact that female plants produce no pollen at all.

An excerpt from the story:

As certain trees burst into bloom in spring, their pollen wafts through the air in a wanton attempt to reach receptive blossoms. Millions of people with allergies pay the price, in sneezing, wheezing, coughing, drowsiness and itchy, watery eyes. They needn’t suffer so much. Cities could reduce the misery by planting street trees that produce very little pollen or none at all.

Street trees weren’t always as allergenic as they are today. Back in the 1950s, the most popular species planted in the United States was the native American elm, which sheds little pollen. Millions of these tall, stately trees lined the streets of towns and cities from coast to coast. Sadly, in the 1960s and ’70s, Dutch elm disease killed most of the elms, and many of them were replaced with species that are highly allergenic.

This has caused trouble for Americans with allergies — as many as 30 percent of adults and 40 percent of children — most of whom are sensitive to pollen, as well as for the many millions who have allergy-induced asthma. Although some pollen can be carried great distances by the wind, most atmospheric pollen comes from plants growing nearby. In other words, the pollen that’s making you sneeze as you walk down the street probably came from the tree you just passed. So it makes sense for gardeners, especially public gardeners who plant trees by the dozens, to pay attention to the pollen their trees produce.

While this particular editorial was written for the New York demographic, what specific species produce the most pollen in the Portland area? Are there tree planting remedies that would lessen pollen levels while maintaining a diverse urban forest of native species?

–Toshio Suzuki