Battling buckthorn

There’s not a lot to like about the stout, spiked branches of the aggressively invasive buckthorn tree. “Buckthorn is spreading actively across the landscape, facilitated by birds eating the berries and spreading seeds,” says Mark Renz, assistant professor of agronomy at UW-Madison and a UW-Extension weed specialist. “The way it is changing the forest understory is really an epidemic in the upper Midwest.”

Buckthorn was imported from Europe over a century ago as an ornamental hedge. But it began to crowd out native plants in woods and natural areas, and nurseries stopped selling it in the 1930s for the most part. A century later, environmentalists and homeowners are still battling it. Now they have a new weapon — Buckthorn Baggies...