The National Weather Service has issued a Freeze Warning for Thursday morning.

“A Freeze Warning means sub-freezing temperatures are imminent or highly likely,” the NWS says. “These events will kill crops and other sensitive vegetation.”

The Freeze Warning is in effect from 2 a.m. to 3 a.m. and from 8 a.m. to 9 a.m. Thursday, April 23, 2015.

Temperatures in the upper 20s are expected in Kane County and across northern Illinois and around 30 in northeast Illinois and northwest Indiana outside the immediate Chicago area.

Sensitive vegetation may be damaged if left unprotected, with patchy frost also possible.

For information on how to protect plants from a freeze, visit this link on the Gardening KnowHow website, which offers the following:

“If you are only expecting a light freeze, you may be able to protect plants in a freeze simply by covering them with a sheet or a blanket. This acts like insulation, keeping warm air from the ground around the plant. The warmth may be enough to keep a plant from freezing during a short cold snap.

“For added protection when you protect plants in a freeze, you can place plastic over the sheets or blankets to help keep warmth in. Never cover a plant with just plastic, however, as the plastic will damage the plant. Make sure that a cloth barrier is between the plastic and the plant.”

SOURCES: National Weather Service, Gardening KnowHow