Purdue News
Purdue News
"The trees are looking dead because they have a fungal disease called sycamore anthracnose," Pecknold said. "They get it every year. But a cool, wet spring like we've had is ideal for the fungus."
The anthracnose fungus spent the winter in stem tissue in your tree. Then, in the spring, it produced spores that rain and wind carried to newly emerging leaves and stems, Pecknold said. Spores germinated and grew into fungal threads that killed leaf and stem tissue.
As long as the weather remained cool and wet, the fungus continued to grow and produce more spores that spread the infection. Cankers formed on wood, girdling stems and cutting off supplies of water and nutrients. Leaves, twigs and buds died.
"However, the magical thing about sycamores is that they are so vigorous they will grow right out of the disease," Pecknold said. "Even though they look very unsightly right now, they'll look 100 percent better in a month. Hot dry weather is fine for sycamore growth, but will send the fungus into a resting state."
The best thing for a sycamore owner to do is to give the tree a little extra fertilizer right now to help push out new growth, Pecknold said. And water the tree if the weather turns dry. Spraying with fungicides generally isn't effective or practical. Raking up leaves and twigs during the year won't rid you of the fungus, since it's living in cankers on the tree.
Anthracnose also infects leaves of white oak, ash and maple, Pecknold said. However, because it doesn't infect stems on these trees, they don't become as unsightly as do sycamores. They are still excellent trees for the home landscape.
However, keep the sycamore's troubles in mind, Pecknold said, if you are thinking about adding a tree to your yard.
"Though the sycamore is a great-looking tree on a stream bank in Turkey Run State Park or out on the back forty or the golf course, I don't recommend it for home landscape plantings," Pecknold said. "It's a very dirty tree. It drops leaves, twigs and bark all year long. And, in addition to anthracnose, it has insect problems. Indiana homeowners who want a large tree should look instead to such trees as tulip poplars, red oaks, white ash or sugar maples."
CONTACT: Paul Pecknold, (765) 494-4628; e-mail, pecknold@btny.purdue.edu
Compiled by: Chris Sigurdson, (765) 494-8415;e-mail, sig@ecn.purdue.edu
Purdue News Service: (765) 494-2096; e-mail, purduenews@purdue.edu
