COLUMBIA — A freeze Thursday night is imminent, the National Weather Service in St. Louis warned, and people should protect delicate outdoor plants.
People should harvest vegetables, such as tomatoes, peppers and basil, as soon as possible, Bart Piotter, owner of E C Piotter and Sons Nursery, said. He said tropical or house plants should be taken inside or covered with something heavy enough to stay in place on a windy night.
"The best way to protect a lot of them is just to throw a cover over them so they stop radiating their heat to the sky," Piotter said.
The loss of heat from the top of the plant is called radiation frost, and it occurs on still, cold nights.
That's the forecast for Thursday night, according to the weather service website. A high-pressure system will produce clear skies and light winds, making ideal conditions for widespread frost.
Caroline Todd, senior market director of the Columbia Farmers' Market, said the freeze shouldn't affect the market. People will still offer cool-season crops such as lettuce, spinach, onions, potatoes and pumpkins as the cold weather sets in.
She said experienced growers at the market know how to handle temperature changes and will still offer as much produce as they can, including greenhouse-grown tomatoes.
"People have gone out and picked every field tomato there is because we all saw the freeze coming," Todd said.
Temperatures are not expected to reach the hard freeze range, less than 28 degrees, that causes annual plants, which bloom once every season or year, to die.
Temperatures should dip below freezing a few hours before sunrise and rise above freezing about an hour after sunrise, the weather service website said.