Some Western Washington poplar trees are turning brown just weeks after leafing out this spring and most will probably never be green again.
Horticulturists say a deep lesion called a canker is attacking Lombardy Poplar trees and the result is usually fatal.
Landscapers covered this area with those trees over the years. They are very prominent along the Fremont Cut, where they provide shade to the Seattle Ship Canal.
The U.S. Army Corps of Engineers, which manages the waterway, confirms the cankers have been found on some of the trees. They are slowly replacing the diseased trees with other more resistant poplars.
The best advice is to clean tools after pruning the poplars and don’t prune at all during wet months when disturbed spores can float on the wind and infect other Lombardy Poplars.
Horticulturist Jason Billingsley said nurseries understand the problem and most no longer sell the Lombardy Poplars but he said there are many more resistant species that give a similar look.