Willow leaves have been browning and dropping from trees in the area at an alarming rate again this summer, after the problem was first noticed last summer. The possible culprit causing the usually lush green leaves to wilt and fall early is fungal leaf drop disease, according to local horticulturalist Joyce Dokter.
But Dokter, who has spent years working with plants and trees, including three years with John Kwasek 'The Tree Man,' said she is not certain the disease is to blame, as others have attributed the affected leaves to the willow leaf miner, a small insect that burrows into and consumes willow leaves.
To determine the cause of the damage, Dokter has sent samples of affected willows away to a laboratory.
Whatever it is, the effects are far-reaching.
There are reports of willows being affected as far away as Edson. But with the amount of moisture there has been in the Bonnyville area this spring and summer, Dokter said the disease has progressed further here.
"We think it occurs when there are extended periods of wet weather and high humidity," she explained. "The affected leaves began with a small red spot on them, surrounded by a halo . eventually the leaves become completely brown and the tree will drop its leaves early."
This is occurring in local willows right now, she said.
Despite the drastic change in colour and loss of leaves, Dokter reassured those worried about their willows the disease usually runs in a two or three-year-cycle, and in all likelihood will not kill the tree itself.
"The trees are resilient and do what they can to fight it off," she said. "And they will recover."
Judy Cabay, owner of Triple T Greenery in Bonnyville, said the disease has not affected trees at the greenery, but she has seen the effects all over town, including on her own property. However, she remains confident the trees will recover.
"There's really nothing you can do about it," she explained. "You just have to let it run its cycle and then allow the trees to rejuvenate."
Dokter hopes to have the results from the tests back later this summer.
