Herb spirals are one of the best ways to plant herbs in your garden. The vertical structure saves space, whilst the spiral design allows you to grow plants with different soil and water needs in the same area. Rainwater drains down from top to bottom, so that hardier plants can grow at the top and water loving plants can grow towards the bottom. Some areas of the spiral will be shadier than others, perfect for those herbs that don’t like strong summer sun. The rocks inside the spiral insulate the soil at night, while the fragrance from stronger herbs can deter pests from more vulnerable plants. In all, herb spirals are one of the most cost-effective and efficient ways of growing herbs and plants, giving you a virtually endless supply of food and flavours throughout the year!
Flattened cardboard boxes
An old metal bucket or some container (if you want a “pond” at the base)
Rocks, slate, bricks or cut bamboo stakes
Soil and compost
Spade, shovel, wheelbarrow, watering can, trowel
Choose a location as close as possible to your kitchen/front/back door and make sure the area receives plenty of sunlight.
Clear a circular area of level ground about 2m in diameter. Of course, it can be bigger than this, but 2m is a good size to spiral around twice. If the area is on concrete or stone, cover with a thin layer of soil. Cover the cleared ground with a good layer of overlapped cardboard to prevent weeds growing through.
Taking your rocks or bricks, from the centre of the cleared ground, begin laying them on the surface in a spiral shape. For a 2m plot, you’ll get two spirals from this. If you’re finding it hard to visualise the spiral, anchor a stake in the centre and using a piece of string, draw the spiral in the soil.
The rocks in the centre of the spiral will be the tallest, so build this between 60cm and 1m tall. As the wall gets taller, you can add gravel to help stabilise the rocks. When the walls are finished, dig a hole and use the bucket to create a pond at the bottom to collect water and attract pest eating frogs, or simply block it off with a larger stone or object.
Now to fill it! Simply treat your herb spiral as a raised bed, so layer first with twigs and other organic material that will rot down. The next layer will be a mixture of compost, manure, wood chips, sand (for plants that like a more arid ground) etc. then finish with a good layer of top soil.
Water very well, and allow to settle for a few hours. And it’s ready for planting!
The spiral doesn’t just have to be used for herbs, you can use it for vegetables too. Where you place them will depend on the requirements of the plant. Hardier plants can be nearer the top, and on south and west facing areas whereas those that like damp soil and shade can be nearer the bottom.
For example, chive and parsley prefer shade and damp while sage, thyme, oregano and marjoram will thrive in the sunny areas. Basil too likes sunshine, but the soil must be kept moist. Coriander and dill like morning sun, so plant in the middle on the east facing side. And hardy rosemary can go right at the top, in the sun. Be careful of planting mint in the spiral as it tends to take over.