MILLER — One of the warmest places in Buffalo County on a frigid February day — or any day — is a geothermal greenhouse along Highway 183 south of Miller.

“It was at a family Sunday supper,” Brock Elsen said about when he, his wife Kerry, and in-laws, Randy and Penny John, first talked about having the 96-foot long, 17-food wide greenhouse as a year-round garden.

Kerry, a Buffalo County Extension educator, had learned about the geothermal technology developed by Alliance octogenarian Russ Finch while leading a 4-H tour of Panhandle agriculture several years ago.

“It was just a little bit of a novelty,” Kerry said about her interest in ordering a Finch greenhouse kit.

The greenhouse at their family farm, most known for its Angus cattle, was finished three years ago.

Kerry’s dad, Randy, said his first reaction to the greenhouse talk was, “Really? You want to garden year-round?”

Penny said she thought it was a “no way kind of a thing,” partly because she and Randy had not seen Finch’s greenhouse.

“I don’t think we were looking to diversify or do something new,” Kerry said with a laugh. “Mom and I like to garden and I thought it would be fun to do something different all year. How fun would it be to eat strawberries in February?”

Something different

Randy said the geothermal system uses above-ground heating and cooling principles that most people understand.

“Heating is simple. Anybody who has sat in a big bay window in the winter knows that’s our heat,” he said, and a reason people go to lakes in the summer is to enjoy a cooler breeze blowing over the water.

Randy said the temperature 8 feet below ground never changes. So for the greenhouse, fans blow air through a tube buried at that depth.

Air circulated into the greenhouse usually is warmer than winter’s outside air temperature and cooler than summer’s outside air temperature.

Penny said another difference from other greenhouses are the polycarbonate panels instead of glass. Randy added that as far as they know, no Finch-style greenhouse has ever been ruined by hail.

The Elsens and Johns hired a contractor to do the dirt work and greenhouse construction, but Randy said he and Brock could have rented the necessary equipment and done the work themselves.

“There are a lot of farmers who could do all of it,” Randy added.

They had no shipping costs because the men picked up their kit in Alliance during a trip to the Panhandle to take cattle to leased pastures. The items fit in a stock trailer and other materials needed were available at home builder supply stores.

Randy said they allowed approximately $40,000 to get the greenhouse up and running. Energy costs have been about $1 per day.

When asked about irrigation, Kerry said, “It’s a faucet and a hose.”

“You don’t really need a sprinkler or a drip system,” Randy added. “... Different plants need different water and at different times. Fifty feet of hose allows you to water the ends and both sides (in the greenhouse).”

Crop inventory

The list of greenhouse crops includes tomatoes, several types of peppers, several types of lettuce, cucumbers, beets, radishes, zucchini, strawberries and a variety of herbs.

Kerry’s son, Cooper, 8, has a pineapple in one pot and small grapefruit tree in another.

There also are dwarf varieties of lemon, lime and orange trees. Kerry said they hope to harvest some citrus fruit this year.

Penny said, except for the trees, all plants are grown from seeds.

Learning curves

Geothermal greenhouse gardening is challenging, even for veteran outdoor gardeners Kerry and Penny.

“We used the soil that was at the site and mixed in compost and some potting soil. The soil out there has lots of clay,” Kerry said.

Penny said the area had been an alfalfa field for many years so the soil had a lot of residual nitrogen. “Some of the growth was unexpected. The plants are huge,” she said.

The gorgeous plants have had lots of vines and leaves, Kerry said, but often “itty bitty” vegetables. “The peppers were the size of a dime when we first got them, but they are getting bigger,” Penny added.

So they won’t apply fertilizer until they know the plants have had time to work the nitrogen out of the soil.

“I think, initially, in my head I thought this was easy. That it would be the same as gardening outdoors,” Kerry said. “... That this was just gardening inside. But it’s not like that at all.”

Challenges include planting at different times of the year and making sure bushy plants in the greenhouse don’t block the sun from other plants.

“We didn’t anticipate how much time it would require. It’s mostly keeping on top of it. The plants grow really fast ... They continue to grow when you think they wouldn’t or shouldn’t,” Penny about other inside gardening adjustments.

Kerry explained that environmental changes shut down outdoor plants’ growth, but that doesn’t happen inside.

It has been difficult to find helpful information, Penny said, because most greenhouse data is from “high tunnel” designs, not geothermal, and other facilities that are used only part of the year.

“A lot of it still is experimental,” she added.

Goals

Their company, Cherry Valley Produce LLC, has limited customers.

The family consistently sold produce — cucumbers, cherry tomatoes, peppers, herbs and zucchini — to the Sumner-Eddyville-Miller school lunch program during the fall semester. Kerry said there has been a pause early in the spring semester, but they intend to have more fresh vegetables for S-E-M before the school year ends in May.

Penny said they have a few area customers, but they don’t do any pick-your-own or farmers’ market type sales. Kerry said they will consider giving tours, but only if people call first to make arrangements.

A greenhouse goal was for the family to have its own fresh produce, plus some to sell, Kerry said.

“Also, that it would pay for itself,” Penny said. “That would be nice.”

“We’re getting there, but it will be a long time before it pays for itself,” Randy added.