The use of chemical-rich herbicides and fertilizers is also incompatible in an authentic eco-garden. “We only use organic pest and disease control agents and organic fertilizers because they’re better for both the environment and the people using them,” says Amber Scott Freda, a landscape designer in New York. “Artificial fertilizers tend to destroy micro-organisms and earthworms which, over time, can result in a dead soil that won’t sustain healthy plants.”
At their simplest, the primary considerations in an eco-garden are water, plants, and landscaping materials. Using water ecologically means many things: encouraging moisture to seep into the ground via permeable paths, capturing and recycling rainwater, and creating rain gardens—shallow landscaped depressions planted with moisture-loving plants that hold excess rainwater until it gradually soaks into the soil.
“A sensible palette takes a global ethic,” is how Pennsylvanian horticulturist Rick Darke describes his approach to plant selection. That means choosing plants—not necessarily natives—that suit the location, taking position, climate, and soil type into account. For example, trees that cope well with low rainfall include California live oak, Monterey pine, and Monterey cypress.
You also need flowers that are rich in pollen and nectar to sustain birds and pollinating insects. Bees, in particular, adore borage, lavender, echinacea, verbena, and salvia. Compost where you can, to nourish your soil later, and seed heads can be left in place to sustain wildlife.
Even city rooftops can be greened up in an eco-friendly way, says Scott Freda: “Since creating a garden on a roof is a lot like gardening on top of a mountain, in New York City we use plants that grow well in the mountains, like conifers.”
Meanwhile, in New Mexico, Design With Nature’s Paschall Garden is a good example of how to marry contemporary architecture with a shrubby desert environment. A “dry” stream bed, vast boulders, roof-water recycling, and naturalized planting contrast with the geometric lines of the property to produce a balanced, and inherently sustainable, result.
Designs Without Walls
But it’s perhaps the “built landscaping” choices we make that have the most impact. Acres Wild takes an appropriately monastic approach: “We use the absolute minimum of hard landscaping—that’s a really important aspect of our designs,” says Roberts. “And rather than putting in huge retaining walls in a sloping site, we’ll specify a lower wall with a gently sloping planted bank because it’s more ecologically sustainable.”
Simple ways to landscape sensitively include avoiding imported materials and choosing locally sourced materials and traditionally skilled craftspeople. Certifiable timber, permeable paving, and natural or recycled materials are good choices, while pine needles, timber chips, grit, and mown areas through lawn grass are all low-impact selections for paths and trails.
Most of all, choose materials that sit well within your own specific landscape. “Genius loci—a sense of place—should be what every good garden design strives for, and it’s not just a visual consideration; it runs much deeper than that,” explains Roberts. This is particularly true of the eco-garden.
In delivering her iconic Dungeness design, Erlam achieved a truly sustainable result: “The garden was located in a Site of Special Scientific Interest so there were many rules to comply with,” she recalls. “Using local gravel, stones, and wood, alongside gentle hummocks of Mediterranean-style planting, was logical in such a protected site. But it actually turned out to be the very success of the garden because nothing looked out of place or ‘over-designed.’”
And when a garden looks as if it has always been there, unfurling itself gently from the ground beneath, you can quietly congratulate yourself on a job well done.