Maximize Return
February 25th, 2016 by Dianna Troyer

Harper Keeler at a small garden near campus. Photo courtesy of the University of Oregon

Harper Keeler at a small garden near campus.
Photo courtesy of the University of Oregon

Landscape architecture professor shares tips for growing lots in a little area

No room for a traditional garden plot?

No problem, says Harper Keeler, a landscape architecture professor at the University of Oregon in Eugene.

Harper knows even a little space can yield a lot of fresh, flavorful vegetables as long as the soil is enriched with compost.

“The principles we use here to maximize gardening space can apply anywhere,” he says.

Harper provides gardening tips and expertise as director of the university’s Urban Farm, president of the Willamette Farm and Food Coalition and adviser to the Oregon Farm to School and School Garden program.

He and his students tend to a 2-acre garden on campus and a 1-acre plot nearby. In March, students transplant onions, broccoli, cabbage, green peppers, tomatoes, onions and shallot seedlings from the greenhouse into various spaces.

Harper dislikes planting vegetables in straight lines. He says honeycomb or cross-hatching patterns maximize space.

To navigate the gardens, he prefers 1-foot-square stepping stones with 4-foot-wide raised beds so plants can be reached easily from either side.

Some gardeners prefer building a keyhole garden—a round raised bed of compost and enriched soil with a slot from the edge to the center—so plants are nourished and easily accessible.

“Mixed varietal crops can be planted together, too,” says Harper. “With this method, you don’t have to wait until a plant is done producing to replant. Companion planting allows you to always have something in production.”

The classic trio—the Three Sisters—involves growing corn, squash and pole beans together in a mound. The corn provides a trellis for the beans. The beans produce nitrogen the corn needs. The squash leaves shade the soil, helping to inhibit weed growth and retain moisture.

Other examples of companion plants include carrots under tomatoes, beets or radishes beneath cucumbers and pole beans with potatoes.

High-yield vegetables such as radishes, greens, carrots or onions also are ideal to plant in a small space.

Instead of spreading out, Harper advocates employing vertical gardening tactics. An inexpensive trellis can be made with posts and a cattle panel, which can be erected like a fence to provide support for beans, melons and tomatoes as they climb.

As melons mature and get heavier, they can be cradled in pantyhose slings attached like hammocks to the panel.

“Tomatoes are basically a bush that needs to be aggressively pruned,” he says. “Leave one or two leaders and have them grow up a vertical string or twine attached to a trellis. Even a single stem can be productive, with tomatoes ripening sooner than if they were under leaves. With no leaves to send their energy to, the plant sends its energy to the fruit instead.”

A variety of containers can be used to grow a vertical garden (see article at left).

“The only drawback with placing containers vertically is that you have to somehow provide a healthy bacterial community that you would naturally find in soil,” says Harper. “You have to import that fertility.”

Even a yard can be considered a garden with certain landscaping choices. Plant a few dwarf fruit trees. Instead of growing non-producing ornamentals, plant berry bushes or colorful leafy plants such as rhubarb, Swiss chard, lettuce or strawberries for a groundcover. Vegetables can be interspersed with flowers, too.

Gardens do not have to be restricted to the outdoors, either. Many herbs thrive indoors in pots, including parsley, cilantro, basil, dill, fennel, rosemary, anise and chives. Certain varieties of tomatoes—Pixie, Patio, Toy Boy, Small Fry or Tiny Tim—were developed as windowsill vegetables and grow well in 6-inch pots.

Harper believes the food the 300 students in his program and gardeners everywhere grow does more than nourish people and tantalize their taste buds.

“Growing and sharing food is a social glue that holds us together,” says Harper, who grew up on the outskirts of New York City. “As a kid, I was exposed to a terrific array of ethnic traditions and learned early the value of sharing and celebrating these traditions, especially as they related to food.

“What still resonates with me all these years later is the deep sense of joy food brings to those who produce, prepare and share it together—from farmers and grocers to teachers, chefs and consumers.”