Ohio Life

My Ohio: Forever Green

A threat to hemlock trees highlights their importance to our state’s natural spaces.

When looking for an icon of Ohio’s wildness, one needs look no further than the dark and shaggy hemlock tree. Sometimes called the “redwood of the east,” the evergreens live for hundreds of years and can reach heights of up to 150 feet.

You may not be familiar with these trees, because they’re not found in most Ohio neighborhoods. But if you frequent parks and preserves, you’ve likely seen their deep-green branches, which darken the palette of the summer forest and capture the snow in their dense boughs during the winter.

Hemlocks are often found in protected natural areas because they make for special places. The dense, cooling shade and organic, acidic soils of a hemlock stand provide habitat for plants and animals that differs from the typical hardwood forests of Ohio. Hemlock groves make for good fishing streams and are home to happy salamanders.

The trees make up a small fraction of our state’s 8 million forested acres, but they are the highlight of my favorite Ohio hiking haunts. Hocking Hills boasts the highest concentration of hemlocks, which visitors encounter during hikes to Ash Cave or Cantwell Cliffs. The trees surround the shores of Lake Katharine in Jackson County and cling to the steep sides of Greene County’s Clifton Gorge.

They are also the tree I most associate with the camping trips of my youth along the Clear Fork Gorge at Mohican State Park or visits to Ritchie Ledges north of Akron, now part of the Cuyahoga Valley National Park.

It’s not always easy to explain why these dark, dense trees that tend to blot out the sunlight are so thrilling to me. They just seem to inspire a contemplative mood, without melancholy. Poet Robert Frost wrote: “The way a crow / Shook down on me / The dust of snow /
From a hemlock tree / Has given my heart / A change of mood / And saved some part / Of a day I had rued.”

They’re a mood-setter, for sure. That’s why I was anxious to learn that the hemlock woolly adelgid — a tiny, aphid-like insect native to East Asia that is sucking the life out of hemlock trees from Georgia to Maine — has made it to our state. Brought to the U.S. by imported nursery stock, the insect now appears to be moving west into Ohio, where it was found in 2012.

Ohioans have learned a lot about non-native, invasive insects in recent years. Many of us have witnessed the ravages of the emerald ash borer, an insect that has killed millions of stately ash trees in our neighborhood streets and city parks.

The attack of the hemlock woolly adelgid is different, in good ways and bad. It’s bad, because hemlock forests form unique habitats. Other native Ohio trees can’t reproduce the cool, acidic soils a hemlock stand creates over time. The (relatively) good news is that there are chemical treatments that can knock back the adelgid and stall its spread. The bug is persistent, but not quite as difficult to kill as the ash borer, which has marched relentlessly across the country.

The Ohio Division of Forestry has had some early success in treating hemlock stands in the Hocking Hills’ Cantwell Cliffs area. Tom Macy, forest-health program administrator for the Ohio Division of Forestry, tells me that the first treatments, applied in the spring of 2013, seemed to be very effective.

He was careful to point out that last winter’s bitter cold likely helped, but the hope is that the treatments can slow the spread of the adelgid long enough for scientists to find a more permanent solution. (Some are hoping that a tiny predator beetle might create a lasting check on the adelgid’s explosive growth.)

I wish them luck in their efforts, because for me, the wild heart of Ohio is found in the places shaded by hemlock boughs.

Randy Edwards is a freelance writer based in Columbus.