WOOSTER -- Secrest Arboretum, like gardens everywhere, has its share of weeds. And Paul Snyder, who works there as a program assistant, has seen their best and worst.
Canada thistle, common moonseed and marestail are the toughest to manage, Snyder said.
"Moonseed completely smothers everything," he said. "Marestail has become resistant to glyphosate (a weed killer) and produces thousands of tiny seeds.
"Jumpseed and bittersweet are the sneakiest. They have a knack for blending in with other plants."
Canada thistle, however, is the prettiest, Snyder said.
It has "wonderful flowers that smell great," he said.
On July 6, participants will discover those weeds and others -- and specifically how to identify and control them -- in the arboretum's Summer Weed ID Class. It's from 8 to 10 a.m. Snyder will be the instructor.
The 115-acre arboretum is at the Ohio Agricultural Research and Development Center in Wooster, about an hour south of Cleveland. OARDC scientists use the arboretum for research on landscape plants, while thousands of people visit its display gardens every year.
Those gardens, it seems, have a secret.
How to know what to look for
"Our landscape beds aren't spotless like everyone thinks," Snyder said. "You just have to know what to look for."
The class will give weed-spotting tips. It also will share details on the arboretum's own weed control practices, including a new strategy against marestail being tried for the first time this summer.
Marestail is a bear to control, Snyder said.
"If you spray it with glyphosate, it branches and becomes almost impossible to pull because it snaps off. But if you pull it, you disrupt the soil and let even more of them grow," he said.
Registration for the class is $10 for members of the Friends of Secrest Arboretum and $15 for nonmembers. Details and a link to register are at go.osu.edu/SummerWeedID. Call 330-263-3761 for more information.
The class will meet in the arboretum's Jack and Deb Miller Pavilion.
OARDC, which is at 1680 Madison Ave. in Wooster, is the research arm of the College of Food, Agricultural, and Environmental Sciences at The Ohio State University.