On the 33-acre Prairie Drifter Farm in central Minnesota, farmers Joan and Nick Olson are cultivating more than just organic vegetables. Alongside their seven acres of crops – including tomatoes, cucumbers and onions – they’ve also planted flowering plants, dogwood and elderberry hedgerows to accommodate species of bees and butterflies essential for the health of the crops.

The Olsons are not beekeepers, but they are part of a movement to reconnect sustainable farming to a healthy environment. As part of a 2013 project by Xerces Society, a nonprofit that specializes in wildlife preservation, the Olsons worked with a biologist to figure out what types of flowers and shrubs to plant to attract bees, butterflies and other insects that pollinate plants. With seeds and plants they received from Xerxes, and those bought with federal grants, the couple also planted strips of grasses and flowers to attract beetles, which help to defend the vegetables against pests.

“There’s now a ton of bees – bumblebees, honeybees, sweat bees – and predatory insects,” Joan Olson said, adding that the flowering plants also add beauty to the land. “It’s good for the habitat but it’s also lovely for us.”

The Olsons’ effort is one that General Mills, in partnership with Xerces and the US Department of Agriculture, hopes to replicate in other parts of the country in a new initiative. The company is contributing $2m to an ongoing project by Xerces to restore 100,000 acres of farmland in North America over the next five years. The project, which will receive an additional $2m from the agriculture department, will bring General Mills’ investment in pollinator habitat restoration to $6m since 2011.

“Most of our products contain honey, fruits, vegetables and other ingredients that require pollination,” said Jerry Lynch, chief sustainability officer at General Mills. “So healthy and abundant bee populations are a priority for us.”

Each year, pollinators contribute more than $24bn to the US economy. Honeybees alone are responsible for $15bn of it by boosting the production of fruits, nuts and vegetables. But bee and other pollinator populations such as butterflies have been in decline in recent years, which has made food giants sit up and take notice.

Nearly 30% of American honeybees were lost last winter, according to the department of agriculture. More than a quarter of the 46 bumblebee species in North America are considered at risk. Another study found that up to 40% of pollinators, including bees and butterflies, are in decline worldwide.

“One in three bites of food that we eat comes from a pollinator, as well as nearly three-quarters of the crops that we eat,” said Scott Black, executive director of the Xerces Society.

Scientists are still investigating what is causing the mass die-off of bees, although they have reasons to believe that pesticides, fungicides, disease and a loss of habitat are all contributing factors. General Mills has been under pressure to protect the bees from exposure to pesticides.

Studies show that habitat restoration is an effective way to increase bee and other pollinator populations. Restoration work involves planting flowers and shrubs on marginal land, typically narrow strips and edges that border crop fields. President Obama established a 2014 task force that developed a plan to boost pollinator populations, which committed to restoring 7m acres of land for pollinators over the next five years.

“Restoration boils down to having the right kind of flowers in the places pollinators live, and having a lot of them,” said Andony Melathopoulos, assistant professor in pollinator health extension at Oregon State University.

As part of its restoration initiative, Xerces will hire six conservation specialists to work with the staff from the agriculture department’s Natural Resources Conservation Service, which has field offices throughout the country. The conservation service works with local farmers and will refer to Xerces those who want to create a pollinator habitat on their farms. There’s no limit to the type or size of the farms that could participate.

Xerces’s specialists will visit each participating farm to help draw up a plan on what and where to plant and how to minimize the use of pesticides. For instance, California farmers could plant baby blue eyes to attract native bees, or narrowleaf milkweed for monarch butterflies.

“Many farmers are good at growing single crops, but pollinator habitat is about growing diversity, something a lot of farmers haven’t done,” Black said, adding that figuring out a good mixture of plants can be tricky. “Some sites might be wetter, some might be drier or on a slope. There’s a lot that goes into what type of flowers will attract which pollinators on what site.”

There are potential downsides to any habitat restoration effort. Some insects that live in hedgerows are pests that could destroy a farmer’s crops. As part of the program, farmers will learn how to minimize this risk by choosing plants that pests don’t like.

Habitat restoration can also be expensive. Costs vary depending on the amount of work needed to prepare for planting and the types of plants used. The least costly habitat might be around $500 an acre, Black said, but a thriving habitat with a dense amount of flowering plants can set a farmer back $1000 to $2000 an acre.

Hedgerows, which consist of woody plants laid out in a straight line along crop fields, can also be costly, between $5000 and $6000 per mile.

Preparing the soil and planting the flowers and shrubs strategically are also more labor-intensive than many farmers realize. This is what farmers have the hardest time grasping, said Black.

“We live in a society where everything gets done now,” he said. “We tell farmers to take a step back and do this first step right so it works in the long run.”

Xerces will measure the success of the project mainly based on the acres of pollinator habitats created. It’s planted roughly 150,000 acres this year, and about 400,000 acres since it started restoring habitats in 2008. The biologists also plan to walk the fields and record the bee count and species, although Xerces couldn’t say how often this will occur.

Creating a habitat to accommodate a variety of bee species can sometimes be even more important than maintaining a high number of bees, Black said. Each species may prefer visiting different flowers and plants – a mixture of species is good for pollination.

“We also want to make a difference with our small piece of land, and make it a teaching tool for our kids and the community,” Joan Olson said.