It may be dangerously cold outside, but inside greenhouses throughout the Garden State, temperatures are set at a comfortable 70 to 80 degrees in order to prepare some of the foods and plants you love so much in the spring.

Farms don't shut down in the winter. Many have greenhouses in full operation to get gardeners' favorite plants and flowers ready for the warmer months.

"We have five greenhouses going now," said Alan Patterson, head grower at Patterson Greenhouses in Howell. "We have pansies and primrose and ranunculus, perennials, geraniums — all the early stuff."

Prep for some of next year's plants actually begin around July of the year prior, Patterson said.

But it's not a cheap task. The plants need to maintain a certain temperature in order to remain viable, which means the heaters are running all night long in this colder weather.

"You know that's going to be a big part of your expense for the winter," Patterson said. "Especially the next couple nights with it being so cold, the heaters are going to get a good workout."

In Pennington, the owner of Jack's Greenhouse & Farm doesn't expect his greenhouse activity to start until late February.

Laura Niederer, Jack's Greenhouse & Farm

"That's when you start to work with all the little seedlings, and then from the little seedlings you transplant them into bigger pots," said Ed Jackowski.

Jackowski said vinca is a big seller in the area when the weather warms up. Deer won't eat it and it can handle extreme sun or drought.

For the holiday season, his greenhouse is hosting rows of poinsettias. Care for the tropical plants requires management of the sun and temperature.

According the state Department of Agriculture, nurseries and greenhouses contribute more than $444 million to the billion-dollar industry.

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