The Nature Conservancy: The Healing Power of Trees
January 15, 2026The Watterson Expressway, also known as Interstate 264, is eight lanes wide where it cuts through the south side of Louisville, Kentucky, and for a long time, the only thing separating the area’s single-family homes, parks and churches from all that traffic was a concrete wall.
But today, martial rows of upright arborvitae, a type of cypress often used as hedges, stand guard between the highway and the working-class neighborhoods on either side. These are just a portion of the 8,000 new trees now shading sidewalks and streets, parks and parking lots, front yards and back yards across a 4-square-mile area. Planted between 2019 and 2022, the greenery has transformed south Louisville, roughly doubling the number of trees in an area that had long lacked the leafy canopy found in wealthier parts of town.