An herb spiral is a coiled garden bed that gradually rises in elevation as it curls in on itself. It has a number of advantages. Its construction makes it visually arresting, especially when viewed from above. This somewhat minimizes the reliance on showy plant specimens to make a statement. Because it builds upward instead of just outward, an herb spiral can contain many plants in a small space. It also conceals some of the plants behind the curve of the spiral, so a few wispy herbs in the mix are less likely to look "weedy" because they aren't all visible at the same time.
One of the biggest advantages of an herb spiral, though, is that the varying elevations in the bed, and its gradual changes in orientation, provide a variety of microclimates that benefit specific herbs. With some planning, this clever construction lets you keep very different herbs together while still offering each the environment it needs (dry, moist, bright, shady, etc.).
While you're planning your spring gardening projects, consider adding an herb spiral to the list. I've written a primer on the subject. You can find it in this month's issue of Maximum Yield magazine. This link will take you to its online location. Just click the numbers at the bottom of the screen and enter 117 (the page number): Spiraling Out
Photo courtesy of Flickr user Jeanne: https://www.flickr.com/photos/jeamac/7237507956/in/photolist