How gardeners can create vertical landscapes in small spaces

It can be challenging to incorporate greenery while living in a dense city setting. Tightly fenced backyards, patios or balconies may not be conducive to sprawling gardens, but there are still options for gardeners to grow plants, flowers and vegetables while effectively using the space they do have.

“Vertical gardening allows you to maximize the surface area of your gardening bed or containers,” explained Weston Miller, Multnomah County Master Gardener Program manager. “Instead of it all sprawling across the ground, if you plant vertically, it allows plants to be planted in closer proximity to each other.”

Vertical gardening uses any available technique to grow plants upward rather than horizontally. Options include raised beds, trellises, living walls, ropes, cages, string, arbors, fencing and railing. All can offer compact solutions for gardeners struggling with space.

For master gardener Harry Olson in Salem, there’s “no downside to growing vertically.”

“When you grow vertically it takes up less real estate,” he said. “Plants love it because they get more sun and air, and they stay dry (during watering).”

Olson is a lifelong gardener and became a master gardener in 2008. He is best known for his grafted tomatoes, which have been featured in publications around the state, and for his vertical vegetable garden showcases. Before the COVID pandemic, it was common for Olson to have around 200 visitors annually at his garden.

Olson lives on a small city lot with a 75-foot-wide yard. Without vertical gardening, Olson said, he “would have a nothing garden.”

In addition to better light and air circulation, Olson said vertical gardening can increase yield and fruit size and allow easier maintenance for watering and harvesting. Even difficult to grow plants like melons thrive.

Another bonus is safety, since it can be challenging to fertilize plants that are on the ground without getting fertilizer on the leaves, Olson said.

“But when you’re in the air, you can just water and fertilize at ground level,” he said.

There are also different levels of vertical gardening depending on the gardener’s skill, Miller said. For some vegetables, sticking a piece of bamboo or a used mop handle into the soil is an easy way to get climbing vegetables to grow wrapped around the pole. A step above that could be cages for tomato plants and then investing in a formal trellis system.

“There’s lots of different materials (for trellising),” he said. “It could be as simple as stakes and wire or twine, or it could be more elaborate with posts and a wire mesh screen.”

Although vertical gardening requires the initial hardware investment for supplies, Olson said that it’s relatively inexpensive to make a trellis using electrical metal tubing, couplers, nettings with 6 inch x 6 inch openers and black UV protected zip ties.

Miller cautioned crafty gardeners to be wary of the weight of their trellis crops: “I’ve seen a lot of poorly made trellises that don’t handle the weight of the crop once it starts growing,” he said.

A common mistake he sees is gardeners waiting too long to put the trellis in the ground. He recommends placing the trellis before planting to make sure plants grow with the trellis. Olson added it’s also crucial to place the netting on or close to the ground to ensure that plants will start climbing it.

The challenge with vertical — or any container gardening — is the need for more fertilizer and water, Miller said. Olson said that vertical gardening also requires more planning: Tall, vertical plants should be on the north side of the garden so they won’t shade the crops behind them.

For gardeners who also grow root crops, which do not work for vertical gardening, Olson said it’s important to leave room in front of the tall vertical plants to grow horizontally as well. He also recommends following succession gardening, especially for cramped spaces. Planting early season vegetables first and harvesting them before planting warm season crops allows for two complete rotations of edible material out of the same piece of real estate.

Plants grow tall on trellises in this raised garden bed.

Master gardener Harry Olson practices vertical gardening to get the most out of his 75-foot-wide yard. Without vertical gardening, Olson said, he “would have a nothing garden.”Harry Olson

Balcony gardening

For even tighter spaces, like balconies, vertical gardening in containers works best, Miller said. A container holding five gallons of soil would be enough to grow a tomato plant, but Olson added it’s always best to err on having a larger container than a small one.

“How well that plant is able to grow depends on what’s below ground; you really need to be in as big of a container as you can put them,” he said. “The bigger the container, the happier the plant and the gardener.”

Olson also recommends that balcony growers realistically assess their space and not make their garden overly ambitious because that can lead to overcrowding. Miller also shared a calculation resource from the University of Delaware for gardeners concerned about the weight on their balconies or patios, but he recommended that gardeners who are considering large containers or raised beds on their decks seek professional help.

“You’re not going to plant a quarter of an acre up there,” he said. “You’re better off to have two to three plants that do really great than six that are stunted from growing into each other.”

He also cautioned against putting a garden on the north side of the patio or balcony because it gets less sun and, “it’s going to have a hard life.”

Living walls

Vertical gardening

– A living wall garden creates a green privacy screen. Photo courtesy of Paradise Restored Courtesy of Paradise RestoredCourtesy of Paradise Restored

Vertical gardening can even take the form of living walls, a landscape design that fastens planters to an exterior wall of a building or home and is maintained through hydroponics, a process that involves growing plants without soil by using mineral nutrients and water. These gardens provide privacy, beautification, and even the opportunity to grow salad greens in otherwise barren locations.

Paradise Restored is one landscaping design company in Portland that constructs these living walls. Micah Dennis founded the business in 1995 after he purchased a small landscaping company at the age of 19. His mission was to transition the business from mowing to a greater focus on outdoor living. Dennis said their philosophy is providing whatever will get a homeowner outside, whether it’s a deck, fire pit or garden.

“It’s that therapeutic benefit you get from being around nature,” he explained. “Even if it’s a balcony or a small courtyard, you can still bring nature into your space.”

To determine if a living wall is right for you, Dennis said to look at the space and pinpoint a vertical wall that’s considered a “dead area.”

“That’s a magnet for either a vine or living wall,” he said. “If it’s in the shade or sun, either one, there are plants that can be planted on that.”

One of the clients Paradise Restored worked with had a small backyard where privacy was a huge concern, Dennis said. Along with planting bamboo in a concrete container to obscure the view into their backyard, they also installed a living wall against the shared duplex’s garage.

“It was an ugly wall, and we turned it into a living art piece,” Dennis said.

Dennis added that there aren’t weight restrictions because the wall of a house can hold “a tremendous amount of weight;” however, he does suggest using a professional service to install these living walls rather than customers trying to install it themselves.

On a different property, the homeowner’s office looked directly into their neighbor’s window, an uncomfortable view to have every workday. He said the solution was building a vertical garden next to their fence on a metal frame with poles fastening it to the ground, so it can support its own weight.

Dennis has also incorporated hanging baskets as well as jasmine vines that crawl up fence lines. “It’s a nice way to handle a vertical garden in a limited space,” he said.

It doesn’t matter how big the outdoor living space is, gardeners and plant enthusiasts can make the most of their environment by growing upward instead of outward.

“It’s an opportunity to be creative,” Miller said, “and to get the most from the space you have in your garden.”

— Aliya Hall, for The Oregonian/OregonLive