You Should Build an Herb Spiral for Your Garden

Every home should have an herb garden. Access to fresh herbs, all the time, will fundamentally change the way you cook and eat at home. While you can buy fresh herbs, they’re expensive, and you have to buy them by the bunch, when you might only need a little. But if there’s fresh dill outside, you might grab a little for an impromptu potato salad. You’ll chop crisp parsley to toss on some pasta, and every single chicken I’ve roasted has been made better by stuffing it with a fistful of mixed herbs from the yard. Herbs generally grow easily, too, but there are tons of them, and they like different growing conditions. Some are tender, and some are perennial, some enjoy shade while others love the sun. For all those reasons, an herb spiral—a unique architectural element for your garden—is a great idea.

Herb spirals are a way for perennial and annual herbs to co-exist

Shaped like a seashell or snail, the raised bed curls inwards and upwards, the outer wall forming a spiral. The inside of the bed is taller than the outside due to the spiral, so you create a long curving row to plant in. Larger perennial herbs are planted in the spiral to provide shade and protection to more tender herbs, allowing them to co-exist and thrive. This design also makes it easier to harvest the herbs, as you can walk around the spiral, and lean over the spiral to harvest. You can elevate the entire spiral, so you don’t even have to crouch.  

Plan your spiral by examining the space

You can make the bed out of anything you’d like, but bricks or large landscaping rocks are common. You could just as easily use wood for a faceted spiral, or landscaping edging for a low-profile spiral. The bed can be as large or small as you’d like, from a simple six foot by six foot imprint, to a sprawling curving wall around the entire garden. The idea is to make it large enough to accommodate the herbs you want to grow, but it should also make sense in your garden from a design perspective. 

Start by making a list of what you’d like to grow, and remember that some herbs are seasonal, like basil and cilantro, and some are perennial, like sage and rosemary. You don’t have to play it safe, either: You can grow teas and edible flowers and medicinal herbs. Some herb seed houses to look for inspiration are Strictly Medicinal and True Leaf Market.

Carefully consider which herbs you’ll want

You should always look at growing zones, and how large plants will actually get. With this list, start surveying where your spiral can go, keeping in mind you want a level space, in the full sun.  Take some measurements. Head to your sketchpad, using those measurements, and start laying in plants from your list into the spiral, with a pencil. Drought-tolerant herbs will go at the top, and less drought-tolerant plants go near the bottom. Plants that need full sun should go on the north or south side so they sun all day. Plants that need some shade should go on the east or west side so they only get morning or afternoon sun, and you should plant them between more shrubby herbs, so they’re protected. 

Consider what will go around the spiral, remembering you’ll be walking on it. Mulch like wood chips or gravel will keep the spiral accessible even in wet weather. When planning for the size of the bed, consider that you’ll need to be able to reach the middle of the bed to access the herbs. Also consider how this spiral will get watered, planning for drip irrigation to be integrated into the bed itself, or planning for the bed to be near a hose spigot. 

Start with a solid base

Start by laying down your layer of stones or bricks in a circle. Then remove enough from the northernmost section to create the planting row. Then start curving the wall inward, and continue inwards until the spiral is completed.
Credit: Amanda Blum

Start by using the materials you’ve chosen to build the base of the bed, which will be a circle. Remember you want enough height on the wall so the bed is deep enough to plant in, so at least eight inches, but 12 or more would be better. While you don’t necessarily need to, cementing in the walls means they’ll last longer and are more stable. Once the circle is built, you remove enough bricks or stones for the width of the row at the northernmost point of the circle, and use them to start the spiral inward. Continue laying at least one course or layer of building material in the spiral pattern, until you reach the middle of the spiral. Remember, the “middle” is actually a smaller circle at the top. Now, start filling the circle in with your planting soil, up to the first level of bricks or rocks. You can fill the center of the spiral with pea gravel or other rocks, remember that you’ll be planting the middle well above where you are now, and this gravel will help with drainage and stability. 

With the base bed filled, you can start building up the inner spiral walls. Add more bricks or rocks to the walls as they move towards the center, filling the inner spiral in with more soil to support the wall. When you arrive at the top of the spiral, fill in the middle circle, and then tamp down the soil for the whole spiral and backfill as you need to. 

Be thoughtful about where you place herbs

Planting time is the most exciting part, because now you can lay out the plants and start putting them in the soil. Consider adding decorative plant labels. You can add edible flowers or plants that attract pollinators. Also consider how some plants spill over the side and hug the wall, like creeping thyme, nasturtiums, and chamomile. Think really hard about plants that spread wildly—like mint, oregano, and lemon balm—and consider omitting them from the spiral. They’re best planted in planters that will contain them from spreading. Make sure you give each plant enough space to grow, and don’t overcrowd them. They’ll fill in the space in time if you let them. 

The more you use the herbs, the better 

Some herbs are seasonal, and will need to be replaced each spring. If you let the plants go to seed, you may find the herbs perennialize, meaning they come back on their own each year. You might add herbs as time goes on, and keeping shrubbier herbs in check through pruning is important. Over time, you’ll learn which herbs you may want more of, instead of those you use less. Mostly, what will keep the spiral happy is using the herbs— so get in there and chop the cilantro, parsley, dill and basil back heartily and use it.