A four-year experiment in growing food all through the winter will end Saturday when volunteers deconstruct a sunken greenhouse behind a church parsonage in northeast Minneapolis.

The makeshift structure called a "walipini" (a passive solar-heated greenhouse with earthen walls) has been an object of fascination, attracting hundreds of visitors since it was built in 2015.

It's also generated at least one complaint, triggering an inspection by the city and resulting in an order that the walipini be modified or removed by June 3.

"The city says it's in violation of code," said Rev. Leah Challberg, lead pastor of Northeast United Methodist Church, whose backyard hosts the walipini. "It's too close to the neighbor's property and too tall."

The church built the walipini as a prototype to show how to grow food in harsh climates. "It fit with our mission of trying to be more sustainable," said garden coordinator Sara Jane Van Allen. The church also maintains a large vegetable garden around its sanctuary.

Such food-growing experiments have been on the rise in recent years, part of the local food movement, leaving municipalities scrambling to keep up. Minneapolis legalized urban agriculture in 2012, allowing backyard chickens, beehives and other small-scale farming. But there was nothing in the city code about walipinis.

An underground greenhouse may sound outlandish, but it's one of several cold-climate growing options being explored worldwide, according to enthusiasts.

"I think it's viable, with the right soil," said Tim Jordan, a Minneapolis architect with an interest in permaculture, who has been working with the church. "It is the greenest approach, using earth to insulate."

Before building the sunken greenhouse, the church asked the city if it needed a permit and was told no, as long as it complied with size and setback requirements, similar to a shed. So volunteers tore out the parsonage lawn and dug an 11-by-7-foot hole, about 6 feet deep, then built a supportive structure using old windows and other salvaged materials.

The first year, volunteers had success growing vegetables throughout the winter. "Kales and collard greens, Swiss chard and broccoli did well," Van Allen said.

But in 2016, after receiving a complaint that the walipini was an eyesore, the city gave the church's previous pastor 10 days to remove it. The volunteers weren't ready to pull the plug on their experiment, so they received an extension, then tried to improve the appearance of the walipini.

"From the outside, it looks like a window set on a pile of dirt," Jordan said. First Ward Council Member Kevin Reich asked staff to study the issue and make recommendations for regulating sunken greenhouses.

"It was determined to be a type of cold frame," said Brad Ellis, manager of zoning administration for Minneapolis. Cold-frame gardening requirements are part of city code, but the walipini was found not to be in compliance. "We kept asking for extensions," Van Allen said.

Other obstacles arose. The neighbor to the south built a shed that blocked the morning sunlight. Then last summer, Challberg, who has minimal gardening experience, replaced the previous pastor at Northeast United.

"I thought it was both amazing and a little overwhelming," said Challberg of the sunken greenhouse. Some of the early volunteers drifted away, and the walipini required more maintenance than anticipated. "It's a little beyond the scope of what our volunteers can maintain well," she said.

Last winter, the walipini was largely "dormant," Van Allen said, although she found kale still growing in it when she checked this spring.

The church has the option of applying for a variance, Ellis said. But volunteers have decided to remove the walipini. They hope to use what they have learned to build a better one on a yet-to-be-determined site. Jordan has been working on concept sketches.

"We'll work out some of the bugs," he said.

To share what they have learned — and to get some help dismantling the walipini — the church is inviting volunteers to a free information session, a tour of another nearby greenhouse and deconstruction of the walipini, starting at 9 a.m. Saturday at 2535 Cleveland St. NE., Minneapolis. Interested parties are asked to register in advance, for snack-planning purposes, at admin@northeastumc.com or 612-789-7462.

Kim Palmer • 612-673-4784

Twitter: @Stribkimpalmer