Let it be said from the outset that the following discussion of mandala gardens is based on a relatively large one, over 100 square meters, that a host of volunteers and I will soon be doing for the Garden of Hope in Guatemala. Our mandala garden, as most mandala gardens are, will be a series of keyhole beds, so in this article, we will be sure to discuss what exactly keyhole beds are, as well as how and why we—permaculturalists—choose to use them. In this particular rendering of the mandala garden, we will also be using the sheet mulching technique in order to create the growing spaces, which means a brief discussion of how and why we sheet mulch is on the agenda. From there, we’ll address how exactly to go about implementing the design.
Then, we are going to get to work.
The Core of the Keyhole Bed
Keyhole beds are about preserving planting space. Rather than having rowed gardens, in which about fifty percent of the area is used for paths, keyhole beds bend that row around a single circle (a hole or compost pit with a path leading to it, resembling an old timey keyhole in a door). Not only does this largely reduce the amount surface area we use for walking, or—more positively put—increases the growing space, but also it makes harvesting that row a one-stop shop, with the ability to reach many of the crops in it from one spot.
In our case at Garden of Hope, we’ll actually be bending rows that are about three meters wide and installing keyholes such that one half is harvested from one side and the other half the other side. This will make our use of space even more efficient. The entrance of our mandala will have an herb spiral, while the center will be a lime tree, and around the inner mandala, there will be a second set of three-meter wide beds encasing it. This type of garden is very well suited to herbs and salad vegetables, the intensive growing and harvesting of Zone One, so we are putting it right next to the kitchen.
The Roots of Sheet Mulching
Sheet mulching (aka lasagna layering) is a popular method of constructing both raised and no-dig garden beds, two things with which alternative agriculturists are enamored. Rather than digging and turning nutrients into soil to make it fertile and loose, sheet mulching builds it atop the ground as is, leaving intact all microorganisms, mycelia and soil life. In the end, a typical sheet mulched area will create nearly of foot of organic material—a mixture of manure, soil, grass clippings, hay, cardboard, newspaper, yard waste, compost, etc.—atop the existing surface, in effect making a raised garden.
A sheet mulch bed (a la Toby Hemenway) starts with watering the space, chopping down and leaving any weeds or greenery, adding any soil amendments needed, and sprinkling a layer of nitrogen-rich material to attract worms. Generally, a layer of cardboard or several layers of newspapers cover the area, and it should be watered down. Another thin layer of nitrogen material, followed by bulk mulch (about 20-30 cm), and roughly 5 cm of compost make up the next levels. The topping should be a weed and seed free organic matter such as straw, bark or wood shavings, to both prevent weed issues and provide a more attractive finish.
The Measurements of Our Mandala
A simple, double-reach keyhole bed is a circle with roughly a two-meter diameter, so that one can harvest the inside half from the keyhole and the outside half from a surrounding path. The keyhole path can be roughly a foot wide, leading to the center of the circle. In order to form a mandala with this, the keyhole beds are put side by side to form a large circle, what equates to a gigantic version of a keyhole bed. At the center of the mandala, there is usually some sort of feature, in our case it will be a lime tree, a must-have for a Central American kitchen garden.
To be somewhat mathematical about it, the lime tree be will be in a bed roughly two meters across, surround by paths of about one meter, so now we’ve reached out to four meters wide. If we add another three meters of width for our mandala keyhole beds, we are now ten meters across. Then, we need at least a thin path giving us access to the outside of the mandala, call it half a meter more to each side. Finally, surrounding the entire mandala will be edible and chop-and-drop hedges to help with food production, mulch material, wind barriers, and possible shade in the dry season, and that will make it roughly sixteen meters across. Our mandala circle will be roughly 192 square meters.
The Inclusion of Biodiversity
Mandala gardens don’t necessarily need to be this large, but we are blessed with a lot of flat open land, recently cleared of coffee trees. This particular space has little shade and is on the southern (sun) side of the plot of land. The Garden of Hope has lots of students to both tend to and eat from the garden, and the garden is meant to provide a safe place for them to learn and grow in their love and appreciation for the planet. Hopefully, this element of our design will demonstrate what can be done with a small area in terms of biodiversity, mostly perennial food production, aesthetics, and no-till techniques.
We are hoping to grow a healthy mix of over twenty different species of productive plants. Our main crop for the inner area will be loose-leaf lettuces, kale, and chard. There will be sugar snap peas for nitrogen, culinary herbs for pest repelling, some fast-growing radishes, and hopefully some tiny wild tomatoes that grow in the area. The thick outer hedge will consist of edibles: pigeon peas, Chaya, moringa, cranberry hibiscus, Jamaican mint, and rosemary. These will be kept pruned so as not to block the sun in wet season but to provide some shade in dry season, and hopefully they will have an understory of nasturtium, which repels pests and provides edible leaves, seeds, and flowers. And, of course, there are limes right at the center.
The Reasoning of This Design
Keyhole beds and mandala gardens create lots of edge, which makes for many microclimates to take advantage of, and the curvy design will also provide a more imaginative space (than the rowed gardens or boxed raised beds) for the children to explore. A mandala is also well suited for a flat, sunny piece of ground, which is what we’ve got, and the keyhole beds make the most of the somewhat compact area we are putting it in, right next to the outdoor kitchen, where the kids will learn to use the vegetables they are growing. We like the no-dig method. We like the easy access to veggies. We like the idea of making something beautiful—not only justifiably functional—with the kids and for the kids.
Feature Photo: Mandala Garden. Image Courtesy Jonathon Engels.