A Guide to Herb Spirals

What is an Herb Spiral? 

An herb spiral is a raised bed of herbs that contains numerous microclimates, ranging from sun to shade, and well-drained to saturated soils. These herbs, many of which are Mediterranean in origin, are some of the easiest and quickest plants to grow. They come with the added benefit of being full of flavor, making them crucial to those delicious home-cooked meals. 

The way the herb spiral works is simple. A spiral design is made up of stone. Various herbs are planted in amended soil according to their natural preferences. Plants that prefer direct sunlight are placed on the sun-face half of the spiral. Shade-tolerant plants are placed on the other side. Likewise, herbs that prefer well-drained soil are placed at the top of the spiral, and moisture-loving ones at the base. This spiral creates a series of microclimates that allow each herb to thrive in your plant hardiness zone.

Before we begin, as a cautionary note, there are plenty of health benefits of certain herbs. Please be sure to check with your physician before using any herbs as medicine, even documented herbal remedies. Some plants may have adverse reactions to already prescribed medications, and it is always best to err on the side of caution.

How Do I Make A Herb Spiral?

Begin by finding a spot in your back yard with enough space for the spiral. For this, you will want to use your permaculture zones and sectors to find the best place for your design. Ideally, you will use your herb spiral for multiple meals a day, so find an easy-to-access location close to the kitchen. Foraging in your garden should never be a hassle! Jonathon Engles from the Permaculture Research Institute further recommends you place your herb spiral in a sunny location, sheltered from winds and heavy rains. This will protect your more tender plants.

The size of the spiral is relative to what feels comfortable for you to manage, though the average diameter is two meters (six feet). To make the outer circle, place a stick at the center of your design with a one-meter (3-foot) string and a stake or chalk. This is used to trace the diameter. The spiral can be on dirt, lawn, or concrete, and works best on even ground. If you are planning on placing it over a paved area, be sure to drill holes through to the soil layer to allow for drainage. When designing over lawn or dirt, set cardboard over the area to prevent weeds from making their way through lower growing areas.

As you work your spiral design in from the exterior, leave roughly half a meter (1.5 feet) planting space between the walls. You can design your spiral for it to work best for you, but if it is too tall or too wide, it is harder to harvest. Some designs include a small pond at the base of the spiral, creating habitat for native amphibians and insects—and an excellent spot for aquatic plants. We recommend placing your spiral with the pond (base level) on the shade side (north if north of the equator).

The winding cone moves upwards, with the central coil at a maximum height of one meter (three feet) and the base wall at 40 centimeters (16 inches) at its lowest. As you're building the walls, fill in the interior space with soil and amendments. Some designers consider sheet mulching this area for fertilization, aeration, moisture retention, and protection from weeds beneath the design.

From stones, bricks, and cinderblocks to bamboo, logs, and even bottles, the materials that make up this spiral are up to you. But, since you're making a beautiful display for your herbs, be sure to pick the best-looking pieces for the outer walls. And if your walls don't fit together perfectly, build one layer at a time. Then, go back and add additional reinforcement to those weaker areas. Remember, this isn't going to be a towering monolith, so you do not have to engineer it perfectly.