The winter weather that blew into Lawrence Tuesday night was a serious shock for plants that have been fooled by unseasonably mild January weather.
Dennis Bejot, director of the Douglas County Extension Office and horticulture agent, said the warm temperatures of recent weeks have lured some plants into sprouting early, and bulbs planted last fall that have started growing probably will suffer or die as a result of the cold.
"They think it's spring and it's time to grow," he said. "If it got down to zero, anything that's up is going to be severely damaged or killed."
The overnight low was 5 degrees, and forecasters predict tonight's overnight low will be minus 3.
Bejot said trees and shrubs should survive the cold snap without any problems, but plants might have ragged leaves and fail to produce flowers in the spring even if they withstand the freeze.
He recommended covering plants, both those that have poked through the soil and those still underground, with straw, hay or light soil.
"About all people can do is cover them with mulch and keep the soil cold enough so they don't grow," he said. "When they start growing, they use their food reserve. If they've been mulched, they might be OK."
Warmers days may be coming. The mercury is expected to rise to 30 on Thursday, and Friday's high is expected to reach 34. Bejot said that's not necessarily good news for struggling plants.
"We really need to have some cold weather to keep them from growing until spring," he said.