An invasive, tree-killing pest has made its way to Portland, spelling trouble for the many native ash trees that cool ...

Portland’s tree canopy will not look the same over the next decade. For many residents, the first signs of the emerald ash ...

The emerald ash borer has made its way to Portland, posing a threat to 100,000 ash trees in the city, and the Oregon ...

The city is hoping to start with planting over 6,000 trees in neighborhoods that lack shade, then upping the number to 10,000 ...

Just outside Cottage Grove at the U.S. Department of Agriculture’s Dorena Research Center, scientists are playing a numbers ...

The city of Portland is launching a major expansion of its citywide tree planting and tree care efforts, including restarting its relationship with the well-known nonprofit Friends of Trees. The ...

If you’re reading this, you probably know the value of the Mercury’s news reporting, arts and culture coverage, event ...

Over the summer, a private arborist noticed an ailing green ash tree at the David Douglas Aquatics Center near Hazelwood-Mill ...

It’s official. The emerald ash borer, a half-inch-long metallic-green beetle, has arrived in Portland. Portland Parks and ...

According to Urban Forestry, current code requires property owners to plant a 1.5-inch caliper broadleaf tree or 5-foot-tall ...