MANHATTAN, Kan. – Last winter was by no means a record-setter, but the damage it caused in landscapes across the Midwest has been showing up for months. Or, in the case of some flowering perennials ... simply never showing up at all.

"By now, however, homeowners should have a good handle on the extent of what happened. They can start taking remedial action," said Ned Tisserat, plant pathologist at Kansas State University.

He admitted, "Initially, the amount of damage was somewhat surprising to me."

But, Tisserat saw injury gradually became apparent on redbud trees, butternuts, mimosas, rose of Sharon shrubs, forsythia, viburnums, spirea, boxwoods, weigelas, blackberry vines, all kinds of arborvitae and junipers. ... Some blue spruce trees actually looked purple.

"I also started getting reports of significant damage to zoysiagrass – especially in low areas where the grass was covered with snow or on ridges where it was exposed to drying conditions," he said.

So, the plant pathologist reviewed all of last year’s weather, trying to figure how a normal Kansas winter could cause so much harm to hardy plants.

"First of all, we suffered through some pretty hot, dry conditions late last summer and fall. Many plants were stressed or damaged even before winter set in," he said. "Then we had a hard and potentially damaging freeze in early October before many plants had acclimated to colder weather. Remember all the dead leaves attached to the trees last fall? They resulted when the leaves froze before fully forming the abcission layer that lets them drop.

"Finally, we did have subzero temperatures in December and January. That’s probably what took care of ‘borderline-hardy’ plants such as mimosa."

So, why did some mimosas survive? And why did a hardy boxwood in one yard die, while the one next door showed little damage?

"This is a time when you can really see that each yard and different areas within each yard often have their own micro-environment. Soil type can make a difference, as can amount of sunlight, wind, drainage, and protection provided by nearby plants or buildings," Tisserat said.