About 5 years ago, as part of a “blitz” the guys from Permaculture Sydney west put a herb spiral in our front yard. It does look like a wedding cake rather than a spiral, buuut what are ya gonna do? The soil the herbs were growing in had compacted somewhat over the years, the tiles were starting to collapse outward and the herbs themselves (what was left of them) were getting very large and leggy despite my pruning, so it was time for a re-do.
After everyone had got here and we had the run through of the day’s activities, the “Herb Team” swung into action. The work was fairly simple, I had had a load of organic garden mix (about a tonne) delivered onto a tarp at the front of the house to replace the soil with, but before we could do that we had to pull out the old herbs and dig out the existing stuff down about 200mm. The diggings were then dumped under the mulberry tree in the front yard to be mixed with the garden mix we didn’t use on the day and the shreddings from any trees that got pruned to make a sort of compost pile/swale.
We kept the lemon grass clump and divided it into three ready for replanting, but the oversized rosemary and lavender bushes were dug out and left for anyone who wanted to take some. The leftovers were composted.
Once the old soil had been removed it was just a case of wheelbarrowing enough organic mix to fill up the bottom tier and then shovel some into the top tier. I still had some tiles left over that were given to me by a mate who is a roofer so it was decided to complete the wedding cake analogy by putting on a third tier. When I did the original one I built in some irrigation pipe so that I could pump water from the tank and connect a sprinkler and water the herb spiral from the centre, but I had never used it so the third tier covered it up.
We finished the work off by inserting the tiles into the second tier to form the third tier then filling everything up with organic garden mix. Once that was completed all of the tiers were mulched with tree shreddings and planted out with new or recycled herbs. The top tier was fitted out proudly with a new rosemary bush!
Unfortunately, the top tier of tiles started to sag outward after the first good rain, so I had to reinforce it with some very thin galvanised wire and a turnbuckle. Every so often I give the turnbuckle a twist to keep the wire taut, in the same manner that braces fix teeth that are out of line it is slowly pulling the tiles into line without busting any. Now everything is growing well and our rejigged herb spiral is starting to produce herbs again so if I get another 5 years out of I will be happy!