Can you grow apples in a tiny garden bed in the midst of a sea of concrete. Or blueberries in a raised bed on a sidewalk?

In an experiment in sustainable urban gardening, they're doing it in Richfield.

Visitors will be able to see how on Saturday's Richfield Beautiful Garden Tour.

The new gardens are at 7610 Lyndale Av. S., in a sidewalk that runs between buildings and the parking lot in the courtyard of Kensington Park, a development with 110 condos and townhouses and stores and restaurants.

Tough shrubs like lilacs and viburnum were planted in the gardens until this year. That was boring, said Colleen Carey, president of The Cornerstone Group, which developed, owns and manages Kensington Park.

"We decided we wanted to do something more innovative about the landscaping," she said. She was inspired at last year's State Fair, where she saw a demonstration garden that featured edible plants for small urban landscapes. Carey hired the firm Ecological Gardens to help design and plant the gardens.

One of the plantings is almost sculptural, with three cedar planting boxes stacked atop each other to form an irregular pyramid. Blueberries, strawberries, chives, borage, mint and other plants grow there. Another "climate victory garden" was planted with perennials such as coneflower and liatris that Carey said hold carbon and fix nitrogen in the soil.

Three-foot-high wire mesh bins in one garden contain potatoes that were planted in layers by poking the seed potatoes through wire mesh from the side. Two narrow columnar apple trees share a bed with other perennials, and a rose, evergreen and rhubarb share a bed with a fire hydrant.

Carey said the gardens show what creativity and careful planning can do, even in tiny spaces.

"We hope [people] will think about where they get their food and how they can use small spaces," she said.

The other half of Cornerstone's garden project is on the roof of the building (it's not part of Saturday's garden tour, for safety reasons). Raised beds on the roof contain heirloom tomatoes that are already two feet high, as well as peppers, carrots, radishes, parsley and other vegetables.

Because of the heat that's expected to bounce off the roof at mid-summer, plants are being grown in buckets or tubs that have water reservoirs in the bottom third of the container. Gardeners will know when plants need to be watered because each container has a pipe with a floating plug that rises and falls with the water level. Shade cloths can be pulled over frames above the plants if the heat gets to be too much.

Because soil is heavy, "we had to be very careful where we put stuff," Carey said. Planting boxes, which are 8 feet square or 8 by 10 feet, were placed over support beams and only cover a small section of the roof.

Tomatoes and other produce growing on the roof will be sold to a restaurant. What grows in the gardens near the sidewalk will be available for grazing by whoever walks by, Carey said.

Maps for Richfield's self-guided tour, which includes residential gardens, are available for $5 at Richfield's municipal liquor stores, City Hall, the Community Center and Wood Lake Nature Center. Gardens will be open to visitors from 1 to 5 p.m. Saturday.

Mary Jane Smetanka • 612-673-7380