They say food brings people together. More and more, gardening does, too.

In towns and cities across Canada, homeowners are matching up with growers in arrangements that put expert hands to work on urban gardens whose bounty they share.

In Joanna Sable’s Toronto backyard, the carrots are up, the pea shoots have sprouted and the strawberry plants are in blossom. Ms. Sable’s work as a chef gives her a keen appreciation of fresh, homegrown vegetables, but her interest isn’t matched with a green thumb. “I thought, how can I do this in a way that wonderful things can come out of my garden?” she said.

So Ms. Sable shares her Toronto garden with a woman she only recently met: Elaine Howarth, who is pursuing a career in urban agriculture but lives in a house with a north-facing yard and not enough room to plant.

“So many people are underutilizing their backyards,” Ms. Howarth said. “Why not use other people’s backyards? Everyone is benefiting.”

The engine of this urban land-exchange movement is the website sharingbackyards.com, which is run by the LifeCycles organization in Victoria, where, according to project leader Christopher Hawkins, the idea began. Thirty-six cities, from Winnipeg to Halifax to Houston, have partnered with the site, and each offers a virtual bulletin board that uses Google maps to help individuals find the right sharing arrangement in their neighbourhoods.

The idea to borrow a backyard came out of a shortage in space at city-run community gardens in Victoria. Someone tacked up a note asking if anyone wanted to share their garden. The concept soon went online, and quickly people in Vancouver joined in. Today, it is so popular that Mr. Hawkins is working to help programs set up, not only in Canada but in such American cities as San Francisco, Santa Fe and New York, and he can barely keep up with queries arriving every day from around the world.

“In the past, people would say ‘I don’t want a stranger in my backyard,’” Mr. Hawkins said. “People are starting to see it’s not a big deal to be connecting with strangers.”

There are many more formal backyard-sharing programs, like The Stop Community Food Centre’s “Yes in My Backyard” program, which plays matchmaker for people in one Toronto neighbourhood. There are commercial endeavours like VegetablePatch, an organic farming business in Ottawa that sells the food it grows in borrowed spaces. And there are volunteer projects like Young Urban Farmers CSA of which Ms. Howarth is a founder – the veggies she grows on a volunteer basis are given to the members of their project.

In Thunder Bay, Kirsten Fritsch recently bought a house from an older man who grew his own food. She didn’t want the soil he’d tended so well for decades to lie fallow, so she posted a notice on the sharing-backyards website and, within two days, had partnered with a group of women through the Ontario Native Women’s Association. They will grow vegetables in her backyard this summer, as well as use her shed, and to prepare the earth ahead of planting season for the group, Ms. Fritsch even rented a Rototiller and did the tough labour of pushing the machine over the garden beds.

“There is no monetary benefit,” she said. “It’s just nice to see someone putting it to good use.”

However, it is not always easy to find someone to plant in your space. There are more gardens available on the backyard-sharing website than there are gardeners looking to plant, and Ms. Howarth has been flooded with offers of free access to people’s yards. In Calgary, Madeline Duffin has hoped to share her organic garden beds, where she grows enough food to feed her son as well as to sell. But growing season has begun and she’s still waiting to find her match.

Once you do find the right person, however, it’s good for both parties, says Ms. Sable.

“I absolutely love being part of this,” she said. “You make something from nothing – that’s exciting.”