The Herb Spiral (or is that wedding cake?)
The herb spiral is another one of the great things to come out of permaculture, the idea being that it provides many different microclimates to grow the different types of herbs such as warmer and drier at the top, cooler, shadier and moister around the bottom. Also, being in the shape of a spiral, it provides the equivalent of a long narrow bed in a smaller space. It is also quite decorative as well as productive, as many of the permaculture ideas tend to be.
I did have help and it was put together on the same Saturday morning as the banana circle was constructed. I needed quite a bit of organic matter to fill it with, more than I could easily home produce. My friends brought some horse manure but I bought in two tons of garden compost. The compost worked well but had a tendency to pack down and in retrospect mixing it with half a ton or a ton of coarse sand to improve drainage would have been a good idea.
I also needed a material to build the spiral with, and of course it had to be recycled material. A good mate of mine is a roof tiler and he had some unused but old tiles that were going to be discarded. He was very kindly able to donate them to the project.
1. Location – The first thing to do is to locate the spiral, preferable where it gets plenty of sun so that the sun-loving herbs can be catered for. We don’t have huge amounts of space in the back yard so we put it smack in the middle of the front yard. I thought it would look good and it does, it is a nice and productive addition to the front yard.
2. Marking out – Once we knew where it was going, it had to be marked out and in the same way as we did the banana circle, the perimeter of the area where the herb spiral was to go was laid out by pushing in a pointed stake in the middle of the area then adjusting the rope to the right radius, then drag it around in a circle, making a circular line in the earth.
3. Clean up and Dig! – The top of the marked out area is cleared of grass and a groove dug around the outside of the circle, something for the outer ring to sit in, in this case the tiles.
Due to the peculiar nature of the tiles, it proved easier to make two concentric circles, a smaller one on top of the larger one, rather than the classic spiral. This works just as well and proves the flexibility of the concept.
4. Making the outer ring - The outer ring of tiles was then sunk into the ground about a third of their height and then soil ;pushed in on both sides to hold them upright. A piece of irrigation pipe was pushed through under the outer ring so that it could be brought up through the middle of the inner ring to enable a sprinkler to be installed in the centre of the inner ring. With the tiles in place, the entire area of the ring was lined thickly to half way up the tiles with wet newspaper, to prevent weeds and grass growing up through it. This ring was then filled up with layers of compost and horse manure.
5. Making the inner ring – Once the outer ring was full of organic matter the inner ring of tiles was sunk one third of their height into the outer ring so that there was an empty cylinder formed on top of the material in the bottom or outer ring. This empty cylinder of tiles is now filled with compost and horse manure too.
6. Plant out and mulch – the herbs can now be planted into both rings and the area mulched, we planted rosemary; sage; tarragon; nasturtiums; basil; marjoram; chives; lemon grass; parsley; some strawberries and few edible flowers such as pansy. Then water the living daylights out of it!
In retrospect I would have ( and still may) twitch up some wire around the top circle to keep the tiles in line, they are starting to move out a bit as the organic matter rots down a bit and subsides. I have not put the sprinkler into service either, we just hand water with town or tank water as we can.
All in all it looks good and helps make our meals more flavourful so I would recommend it as a worthwhile project for anyone looking to live more sustainably in the city.
