In Gaia’s Garden, Toby Hemenway presents permaculture. Permaculture is a design method that helps humans design and re-wild landscapes following nature’s patterns. Robust enough to invigorate and regenerate landscapes across continents, permaculture has found astounding success is every climate. Hemenway takes it to the home-scale, offering tools to create self-sustaining systems that increase functionality and yield abundance. Toby Hemenway is the keynote speaker at the ELA Conference & Eco-Marketplace on February 25, 2010 in Springfield, MA.
Designing the Ecological Garden
An ugly landscape cramps the soul, while a beautiful one invites, relaxes, and heals the viewer. Yet a garden that is designed only to look pretty barely skims the surface of what landscapes can offer. A place designed according to principles deeper than those of surface appearance can still be beautiful but will also shelter wildlife, feed people and animals, purify the air and water, store carbon, and be an asset to Earth.
No human designed an alpine meadow, a tropical forest, or a creek-side grotto, yet these wild landscapes are never ugly. They follow a larger natural order that seems to ensure beauty. In the previous chapter we began to glimpse a few aspects of nature’s order. Now we can use these principles and patterns of nature to design our gardens.
A natural landscape is patterned in ways that harvest the energy (sun, wind, heat) and matter (water and nutrients) that flow through it, casting a living net that collects these resources and shuttles them into myriad cycles that transform them into more life. Nearly everything that enters a natural landscape is captured and used, absorbed and reincarnated into vibrant biodiversity. Anything produced in that landscape, from by-products such as sugary root secretions to “wastes” such as manure and molted insect casings, is recycled, swallowed up again, and reincorporated into new living tissue. And the landscape “learns” as it goes, selecting and improving the patterns that work best. Each captured bit helps build and refine a network that gets better than before at catching what comes its way.
Billions of years of evolution have left few loose ends in nature. One creature’s waste is another’s food. Nearly every niche is tightly held, every habitat is packed full of interconnected species. Anything faintly resembling a resource will be used: if one species can’t use it, another will.
It is this interconnectedness-this linking of one species’ “outputs” to another’s “inputs”- that we seek to re-create in the ecological garden. Unfortunately, we don’t have billions of years to wait while our gardens evolve to the immense “webiness” of the natural landscape. But we have another tool: our creative minds. We can consciously evaluate
the pieces of our landscape and use permaculture
The most basic garden bed contains single rows of plants with paths between each row. In this layout, paths consume about half of the soil area. A raised-bed garden, in which paths fall between every three or four rows of plants, is an improvement, sacrificing only about 30 percent of its ground to walkways while leaving the beds narrow enough for the gardener to reach the center. Here, a simple change in geometry has eliminated almost half the path space. But we can do better and create an eye-pleasing design while we’re at it.
If we bend that rectangular raised bed into a circle – or, more accurately, a horseshoe shape – even more path will disappear. By a simple trick of topology, the path shrinks to a tiny keyhole shape, which gives this space-saving garden layout its name: keyhole bed.
Here’s what happens. If we wrap a typical 4-by-15 -foot raised bed into a U shape with a small central opening for a path, we cut the path down from about 22 square feet (figuring an 18-inch-wide path down one side of the raised bed) to 6 square feet. Less than a quarter of the ground is surrendered to paths. I won’t torture you with the math that would prove this to the skeptical-as any publisher knows, each successive equation in a text puts half the remaining readers to flight.
Keyhole beds have aesthetics as well as mathematics going for them. Bringing curves into a garden eliminates that “soybean field” quality that emanates from ruler-straight beds and rows. With the exception of falling apples and other gravity-driven phenomena, nature never takes the shortest distance between two points. Instead, nature meanders, drifting in graceful but efficient undulations from here to there. It’s humans who have become enamored of the unswerving, direct route. But in our gardens, we meet nature more or less on her own terms. Just as a straight stretch of interstate highway invites narcolepsy, linear gardens are monotonous, too. Curves and circles lend surprise and whimsy to a garden. What a bonus it is that they happen to be more efficient, too.
More benefits of keyhole beds: if we point the central path toward the south and locate tall plants such as tomatoes or sunflowers at the back, or northern edge, the bed creates a U-shaped sun bowl that traps warmth. The toasty microclimate inside is a good place for tender or heat-loving varieties. They are easy to irrigate, too. A single minisprinkler in the center will cast a circular spray pattern to drench the whole bed.
The Herb Spiral
We can go a little deeper into the use of shape and pattern in the garden. Permaculture principles tell us to begin at our doorstep, so let’s put an herb garden along the path that starts at our back door. OK, in goes the oregano, next to it a couple of types of thyme, then chives-we like chives, so let’s plant five of them-and past those, a few parsley plants and a little mint. We add a dozen more favorite herbs and spices, and finish off with three varieties of sage. Soon, about twenty-five plants are dotted along the path, stretching well into the backyard. Those sage plants are pretty far away. On a raw wet day, we’ll need to don boots and a jacket before we’ll want to gather herbs. It’s more likely that, with a little pang of guilt, we’ll reach into the cupboard for dried sage and skip the chives. Plus, that little herb garden needs about 30 feet of path to give easy access, and every inch of path is one less inch of growing space.
What if we design the herb garden using a different pattern? Instead of a straight-or even meandering-line, let’s fold up the path somehow so that the whole affair takes less space. We could just plunk the herbs into a standard raised bed, leaving a rather dull rectangular patch outside our door. That would save space, though some of the herbs might need quite a stretch to reach. But let’s be more creative. Here’s where a little knowledge of shapes and patterns comes into play.
This is a perfect spot for an herb spiral. An herb spiral coils up 20 or 30 linear feet of pathside plants into a helical pattern about 5 feet across. It’s not just a flat spiral, either. Here’s how it works.
An herb spiral begins as a mound of good soil about 3 feet high and 5 feet across. To turn this mound into a spiral, place football- to fist-sized
rocks in a spiral pattern that winds from the bottom inward to the top, with the bigger rocks at the bottom. Leave about a foot of soil between the tiers of the rock spiral.
Now it’s time to install the herbs, winding them up the spiral. This coils about 30 linear feet of row into a much smaller space. All the herbs can grow right outside the door, using only the path space necessary to walk around the spiral. Plus, mounding up the soil means we can reach the central herbs without bending over very far.
Combining the spiral and mound patterns into a three-dimensional helix does more than save space and effort. Its mound shape means the herb spiral has slopes that face all directions. The sunny, south-facing slope will be hotter than the north. The east-facing side, which gets morning sun, will dry out earlier in the day than the west one. The soil at the bottom will stay wetter than that at the top. We’ve created an herb garden with different microclimates. So we plant accordingly, locating each herb in a suitable environment. Varieties that thrive in hot, dry climates, such as oregano, rosemary, and thyme, go on the sunny south side near the top. Parsley and chives, which prefer cooler, moister climes, find a home on the north side. Coriander, which seems to bolt in too much hot sun, can be stationed on the east side, protected from afternoon scorchings. Other herbs can snuggle into their best sites as well.
A few tips on building an herb spiral:
• The plants listed in the figure are merely examples. Choose herbs you use-not everyone needs echinacea. And they don’t have to all be herbs, so feel free to include lettuce and other salad greens, strawberries, flowers, or any other small plant that you use often.
• To save on topsoil, place a few rocks, concrete rubble, or a heap of subsoil at the base of the mound, then build over
• To water the spiral easily, run plastic irrigation tubing (1/4 or 1/2 inch) inside the mound, emerging from the top, and
attach a minisprinkler.
• The loose soil of the new spiral is likely to settle, so water it thoroughly (without washing it away) after piling up the soil and settle the soil without compacting it. You may need to add more soil after doing this.
• Consider sinking a small basin or tiny pond (1 to 3 feet across) at the bottom of the spiral. Watercress, water chest-
nuts, and other edible pond plants can grow here.
Built with attractive stone, an herb spiral can be an eye-catching central feature of any garden.
Building and Planting a Keyhole Bed
To create a keyhole bed, begin with a circle of soil about 8 to 10 feet in diameter pierced on one side by a path to the center. Keyhole beds can be created by shoveling fertile topsoil into a horseshoe shape, but I prefer to build them by layering up, lasagna-style, leaves or other compostable organic matter, newspapers, and soil, using a technique called sheet mulching (see Chapter 4 for details). In a keyhole bed, the plantable zone is about as wide as in a standard raised bed: 3 to 5 feet across. The access path into the bed can be narrow, a foot or so wide, but the central circle of path needs to be big enough to turn around in, about 18 to 24 inches in diameter.
You can plant a keyhole bed using the zone system (look ahead to see Table 3-3 and accompanying figures for an explanation of zones). Put the most frequently picked plants closest to the center. That means that herbs, greens, and other veggies harvested and eaten daily should border the central path. Behind these, place plants that get picked only every few days, such as peppers, bush peas and beans, eggplants, and others. These are still easy to reach without a stretch. At the back of the bed, install long-term crops and those that are harvested only once. These include potatoes, carrots, and other root crops, plus what I call the Red Queen veggies–cauliflower, iceberg lettuce, and cabbage-because it’s “off with their heads” at harvest. These back-row plants might be a bit out of reach if the bed is more than 3 feet deep; thus what I am about to suggest will shock those gardeners who are zealous adherents of the double-dig method. To harvest these plants, step onto the bed (gasp!) and pluck. One footprint per season isn’t going to annihilate soil porosity and structure. If the idea of stepping on light, fluffy soil is simply too appalling, lay down a board to stand on, which will limit compaction.
Keyhole beds abound with creative possibilities. A whole circle could be dedicated to tomatoes, with a few companion culinary herbs such as basil or chives at the inner margin. Or use the circular geometry to balance sun and shadow: Place crops that wilt in midsummer’s full blaze to the east of taller sun-lovers, shading the tender ones on scorching afternoons. To trellis vining plants, curve a length of fencing around the bed. If salty coastal gales or the desiccating winds of the plains buffet the garden, plant tall sturdy crops such as Jerusalem artichokes or a stocky breed of sunflowers on the outside of the beds as a windbreak. Of course, keyhole beds work for flowers, too, letting us stand, shears in hand, in a circle of brilliant color as we contemplate filling a vase or three.
Keyhole beds are round, whereas most yards are square. So what about the margins, those little triangles of unused ground at the corners of these beds-isn’t that wasted space? Not at all. Every garden needs insect-attracting flowers, or perennial nitrogen fixers such as Dutch clover, or a good wind-and-weed barrier at the edges to stop weed seeds blowing in from your neighbor’s less-than-immaculate land. We could fill the margin with robust mulch-providers such as fava beans or comfrey. It could be a perfect spot for a small fruit tree. Or we can just expand the bed to fill the corners. There’s no rule that says a keyhole bed can’t be square rather than round; it’s the central path that defines it.
Planting more than one keyhole bed expands the possibilities. Keyholes can extend to the left and right of a central walkway. An undulating path flanked by keyhole beds can wrap around a house to make an attractive Zone 1 garden.
A further modification of the keyhole scheme is the mandala garden, a set of four to eight keyhole beds arranged in a circle with one more bed in the center, and a path entering the mandala from one side. A mandala garden combines beauty and efficiency to create a magical effect. Few designs can fit more growing space into less area, and the more mystically inclined would say a mandala garden brings a spiritual aspect to a piece of ground.
Other Natural Patterns in the Garden
Let’s examine why the herb spiral offers so many rewards. This design winds a straight line into a spiral and then drapes this two-dimensional pattern over a three-dimensional one-the mound of soil. The combination spawns a wealth of what are called synergistic effects-the unexpected benefits of a new collaboration that neither partner alone can offer. These two patterns also interact with the environment-sun, shade, time of day, and so on-as well as with people-saving labor and space, encouraging use, looking attractive-in many more ways than a static row ever could. Clever use of natural patterns in garden design can often generate delightful bonuses.
Nature itself is full of these patterns. The spiral and the related helix (a spiral stretched into three dimensions, like a corkscrew or herb spiral) are particularly abundant. Snail shells, the pattern of seeds in a sunflower head, ram’s horns, hurricanes, galaxies-all form spirals. The pattern of leaves or branches extending from a stem often unwinds in a helix, which minimizes the amount of shade cast by each leaf on the one below. Spirals are often the result of growth or expansion.
Here are a few more of nature’s patterns that are useful for gardeners to recognize.
Branches. Branching patterns are used in nature to collect or disperse nutrients, energy, and water. Tree branches spread leaves over a wide area to better absorb sunlight. Forking roots gather nutrients and moisture.
We can apply our observation of branches in the garden. California designer and educator Larry Santoyo of Earthflow Design Works constantly uses patterns in his landscape designs. Inspired observation of a leaf taught him a novel design for garden paths. In one of his classes that I visited, he passed leaves to his students. “Look at the branching veins,” he told us. “They use the least possible space to get sap from the green cells, the photosynthetic cells, to the rest of the plant,” he pointed out. The leaf’s central vein was thickest, the main branches from it were half the size, and from those extended tiny veinlets for ferrying nutrients to, and sap from, each cluster of cells. The veins themselves don’t gather much light, so it behooves a plant to minimize them. “Why don’t we design garden paths like that? Why didn’t anyone see this?” Larry asked. “You make a big central path for a cart or wheelbarrow, and smaller ones branching off of it for foot traffic to the beds. You save a lot of space and have a natural flow pattern.” I was struck by how original and useful Larry’s observation was. He’s designed many successful gardens using this pattern, and others have copied him.
Branching patterns are an efficient way to reach all the points in a large area, while moving the shortest distance possible. A single branch is also easy to repair if damaged, and its loss has only a small effect on the whole system or organism. Anywhere collection or dispersal needs to be done in nature, you can find branching patterns: the tributaries of a river system, the seedheads of Queen Anne’s lace and other umbel flowers, blood vessels, the forking zigzag of lightning bolts, or the ever-finer divisions of tubing in a drip-irrigation system. Branches are a common pattern in nature and in our gardens.
Branching garden paths, modeled after a leaf. The pattern of a leaf’s veins is a space-conserving way to deliver nutrients to the leaf cells without sacrificing precious light-gathering surface. We can use the same pattern for a garden’s paths, which minimizes the growing area lost to our pounding feet.
Hemenway, Toby. Gaia’s Garden: A Guide to Home-Scale Permaculture – Second Edition
Chelsea Green Publishing, 2009
Excerpt printed by permission of the author.
Toby Hemenway is the author of the first major North American book on permaculture, Gaia’s Garden: A Guide to Home-Scale Permaculture, and an adjunct professor at Portland State University. He is also Scholar in Residence at Pacific University. After obtaining a degree in biology from Tufts University, Mr. Hemenway worked for many years as a researcher in genetics and immunology, first in academic laboratories including Harvard and the University of Washington in Seattle, and then at Immunex, a major medical biotech company. At about the time he was growing dissatisfied with the direction biotechnology was taking, he discovered permaculture, a design approach based on ecological principles that creates sustainable landscapes, homes, and workplaces. A career change followed, and Mr. Hemenway and his wife spent ten years creating a rural permaculture site in southern Oregon. He was associate editor of Permaculture Activist, a journal of ecological design and sustainable culture, from 1999 to 2004. His current project is developing urban sustainability resources in Portland, Oregon, where he now lives. He teaches permaculture and consults and lectures on ecological design throughout the country. His writing has appeared in magazines such as Whole Earth Review, Natural Home, and Kitchen Gardener.