What Is An Herb Spiral?
An herb spiral is an idea commonly implemented in permaculture gardens. It is a way of growing a wide range of herbs, each of which enjoys different moisture and light levels, in a relatively small area. It can be a great solution for small gardens and allotments as it can increase growing area and maximise the edge effect. It also looks attractive and mimics one of the patterns commonly found in nature.
One of the great things about herb spirals is that the idea is a flexible one. You can adapt the idea to suit your exact circumstances and to suit your needs. Use your imagination and you can create a herb spiral for next to no financial outlay. I have created two herb spirals now, the first, a small one, at an allotment I used to have and the current much larger incarnation, on my current 1/3 acre property. Neither cost a penny as they were both constructed using materials found on site. The only expense was for the herb seeds and those costs were reduced by cuttings gifted from friends and family.
A half-planted hugelkultur herb spiral with stones
The Best Location For An Herb Spiral
The first stage in making a herb spiral is to decide where it should be located. Herb spirals are usually best situated in full or partial sunshine in a sheltered spot that is protected to some degree from the prevailing winds. You should avoid areas of deep shade and frost pockets in cold climates and in hot climates, may wish to consider some sort of protection from the most intense sun, especially if you wish to grow herbs with higher moisture needs or those which are prone to bolting in hot weather.
It is also important to consider practicalities when deciding where to create your herb spiral. Bear in mind that herbs are required often and will be most commonly used in the kitchen. Locate your herb spiral as close as possible to your kitchen, so you can just nip out every time you wish to harvest some herbs for a meal. A herb spiral will be less well tended and herbs less used if you locate your herb spiral too far from your home.
Another consideration is that the smell of the herbs can be used to effectively reduce pest problems on other garden beds and borders. A herb spiral should be placed, if possible, close to other growing areas, so they will benefit from the protective properties of the aromatic herbs. In the photographs beneath, you can see how a herb spiral placed at the edge of a growing plot allowed the creation of a productive yet natural space.
An empty plot marked out with herb spiral in the foreground
The same organic growing space around 3 months later
Building Your Herb Spiral
The first thing to understand about a herb spiral is how it creates a range of different habitats. Understanding this is key to building one that keeps all your herbs happy. The top of the herb spiral will be drier and more free draining than the bottom of the spiral and the south side (or north in southern hemisphere) will be warmer and brighter than the north side.
The spiral should circle down clockwise from the center. The lowest part of your herb spiral should be to the north in the northern hemisphere and to the south in the southern hemisphere. Herb spirals can differ in size depending on how much space is available. The higher the herb spiral is in the middle, the more pronounced the shade to the lowest sections will be. In a warmer climate, the herb spiral should usually be taller, while a more shallow ones are better in a cooler temperate climate like the one where I live.
Once you have decided on a location for your herb spiral, the first step is to create the structure. How you create the rise on your herb spiral will determine whether it will be a temporary or more permanent structure. Place cardboard if building on grass or weedy soil to create a base for your spiral and reduce the need to weed. You can then choose one of two methods:
Build up a mound using biomass (branches and twigs, leaves, straw, bracken etc.) as you would to create a hugelkultur ('mound culture') vegetable bed. Cover with topsoil / compost and then mark out the spiral on this mound using stones, short sticks or canes pushed into the mound or whatever else you have to hand. This is a temporary herb spiral and will flatten and enrich the soil as it breaks down over time.
Build the spiral from the base up using stones and rocks (as in the photographs above), logs, reclaimed bricks, even glass bottles or other recycled items from your home fixed in clay/mud. You can then fill in the spiral using biomass, soil and compost as above. Though this will sink a little over time, the structure of the mound itself will remain and, with yearly application of a little compost created in your garden, this sort of herb spiral will form a far more permanent garden feature.
A Planting Scheme For Your Herb Spiral
Here you can see the herb spiral with the herbs labelled
Once you have created your herb spiral's structure you will of course have to go on to think about what you are going to plant in it. Deciding what goes where involves having a little understanding of the needs of various herbs. Here are a few hints to help you grow some common herbs:
Rosemary, Thyme, Lavender, Marjoram and other Mediterranean Herbs: These like dry and fairly warm conditions. Set them at or near the top of the herb spiral on the south facing side (north in the southern hemisphere). Rosemary and lavender should be top centre of your herb spiral because of their deep roots.
Sage, Oregano: These herbs are amongst those that also thrive in dry conditions but benefit from the shade of plants above them on the herb spiral.
Coriander, Dill, Basil: These plants like more moisture than the above and yet still benefit from being in full sun, (at least in cooler climates) so should be placed lower but on the sunnier side of the spiral.
Parsley, Mint, Chives: These plants and others will enjoy shadier and moister conditions on the cooler side of your herb spiral near the bottom.
These are just some hints to help you get started with growing your own herbs in your garden using this practical permaculture idea.