How to Build an Herb Spiral
Herb Spiral or Mound
Location in the Garden and Size
It doesn't matter at all whether the spiral will be so large that you'll need a construction excavator to build it, or if it's barely a metre across. And if you don't have enough space or materials for a spiral, a smaller mound will work just fine.
What's important is a sunny spot, so you can work with the different needs and requirements of the plants you're growing.
The finished spiral will become a garden centrepiece that's amazing to look at when it's in full, lush growth. And since you'll mainly be using the herbs in the kitchen, it should be accessible and close to the house!
Spiral
It turns to the right (anticlockwise) so that its beginning is oriented towards the northern shaded side. As it rises upwards, you'll create at least three different growing zones with different conditions. The base, where it will be more moist and less sunny, through the middle section, up to the top, where Mediterranean herbs accustomed to proper heat will thrive.
Soil
It's necessary for the soil at the top to be very well-draining, while at the bottom by the base you want soil that's more humus-rich and nutritious (for example, thanks to generous use of compost). Better drainage can be achieved by mixing in sand or even better, building rubble from old plaster. The lime contained in this material will create an alkaline soil reaction, in which southern plants will truly thrive.
However, the most important elements are the stones. Always at least half sticking out! They will form the walls of the spiral. After being heated by the sun, they'll store heat, which will warm up the heat-loving herb residents. However, moisture will be retained beneath them, so the spiral won't dry out as quickly. And finally, they'll also serve as stepping stones in case you need to step onto this vertical bed for harvesting or maintenance (stepping on beds outside designated paths is the greatest sin, after all!).
Feel free to fill the deep interior with large stones or even better with an old tree stump or logs and thick branches. These will be good partners for all soil organisms and processes that naturally increase substrate fertility.
True connoisseurs will build a small pond even before the very beginning of the spiral. A simple liner or even a sunken old pot will do. This will help the spiral's ecosystem and can be a space for growing additional moisture-loving plants that are pleasing to the eye.
Following these principles (protruding stones, different soil types, and planting according to height), you can simply create a mound.
Composition
From the ground, even before the spiral begins to wind upwards, there's a suitable spot for mint, dill and parsley. On the first level, completely separated from the surrounding lawn, basil with marigold, oregano and chives with chamomile will thrive. The upper levels, under your sowing guidance, will be dominated by savory and sage. At the top, you must leave space for the most interesting pieces, for which you toiled with your spade. Namely tarragon (wormwood), wild thyme, thyme and the crown of the spiral will be rosemary.
This order is suitable not only because of the different conditions that the given plants require, but also for beneficial neighbouring relationships and mutual support during growth.
You can pre-grow the inhabitants of your future creation at home directly from seeds right now. And what else can you do already? Look for materials, of course! Stones, wood, old rubble, soil. Don't just sit there – get out and explore your surroundings!
Don't have a garden large enough even for a mound, but still want to have your own herbs? Read our tips on growing herbs at home.