by Connie Oswald Stofko
In general, gardeners in Western New York are encouraged to keep perennial leaves and stalks in place to create winter interest, but one plant you should cut down is the iris.
“We encourage folks to cut the iris leaves down after the first heavy frost,” said Marilee Farry, president of the Western New York Iris Society. “What is important is not to throw those leaves into the compost pile but to either burn them or put them into the garbage can.”
The iris borer moth lays eggs on the leaves in autumn, she explained, and the eggs overwinter on the leaves.
In spring, the eggs hatch into larvae and “eat each other, until the winner moves down the iris leaves (fairly rapidly) into the rhizome and usually devours it,” Farry said. (Yes, the iris borer larvae are proven cannibals, with only one surviving in each iris, according to the American Iris Society.)
If you get rid of the eggs, you get rid of the problem.
“I cut my leaves every year, and I have not had the iris borer for the last two years,” she said.
If you haven’t had any problems with the iris borer, should you still cut down your iris leaves? The answer is yes.
“One never knows where or when those ugly moths will fly,” she said.
See more information on the care of irises here, which has also has photos of the iris borer larva and the damage it can cause.
The meetings of the WNY Iris Society are open to everyone. See their upcoming events here.