This pattern does much more than save space and effort. It encompasses many permaculture principles. This herb garden is also used here as an educational tool to encourage people to grow their own organic food, and to recycle as much as possible.
The herb spiral has slopes that face in all the directions of the compass. The south-facing slope will be hotter than the north. The east-facing side, which gets morning sun, will dry out earlier in the day than the west one. The soil at the bottom will stay wetter than that at the top. We create an herb garden with different microclimates.
To build the spiral, we need first need to select a site, about 2 meters across.
Ideally we want it to be close to the kitchen but if this means that we have to site it in the shade then we will have to settle for a longer walk. This is at the heart of permaculture principles. The sitting of your spiral will depend on finding an area which receives enough sun light to keep Mediterranean herbs happy and not so far away from the house.
“Ecological gardening moves away from the ‘one role for each plant’ philosophy. Plants are intimately connected to the sun, soil, water, and air, to each other, to insects and other animals, and to people. Also, they transform all that they are tied to. When we understand the multiple roles that plants can play, we can link together their many functions in intelligent ways. Then we can design gardens full of resilient, interconnected networks of life.” Tody Hemenway – Gaia’s Garden.
We plant accordingly, locating each herb in a suitable environment. Varieties that thrive in hot, dry climates, such as oregano, rosemary, and thyme, go on the sunny south side near the top. Parsley and chives, which prefer cooler, moister climes, find a home on the north side. Coriander, which seems to bolt in too much hot sun, can be stationed on the east side, protected from afternoon. Other herbs can snuggle into their best sites as well.
- To save on topsoil, we place a few rocks or a heap of subsoil at the base of the mound, and then build over that. As the wall gets higher, we can start to infill with gravel (or sand); this is for drainage but will also stops a collapse as it gets higher. Remember to leave enough space for compost and top soil. It can be treated as a raised bed.
- We use sheet mulching technique to build up the soil and keep most of the weeds away.
- To water the spiral easily, we can run plastic irrigation tubing (1/4 or 1/2 inch) inside the mound, emerging from the top, and attach a mini sprinkler.
- Consider sinking a small basin or tiny pond (1 to 3 feet across) at the bottom of the spiral. Water cress, water chestnuts, and other edible pond plants can grow here.
- Built with attractive stone, an herb spiral can be an eye-catching central feature of any garden.