Recycled Bottle Herb Spiral
Hilary Wilson explains how to build a simple herb spiral using recycled bottles.
This two-story spiral is above ground level over an established lawn and old tree stump on the northeast side of a house – just outside the kitchen, of course!
Using the stump as the centre and high point of the spiral, I measured two meters in diameter so there was a one-meter reach to the centre from any side. The spiral is on a slight slope, so I graduated the bottle sizes to have smaller bottles uphill and taller, wine-sized bottles on the downhill to make up the base level. This isn’t always necessary, but helps if you are building a raised garden and have deep rooting herbs like parsley.
Before building up, I covered the base of my raised bed-to-be with a thick layer of old newspaper and cardboard to discourage the lawn grasses from creeping into the herbs’ territory.
Once you have laid out however many and which bottles you want to use as your base circle, bury the inverted bottles past the neck while twisting and pushing to get them firmly in place. Using a bag of organic potting mix and or a soil/compost mix, fill in the base circle layer to top of the bottle wall. About a foot in from the outer wall, I began the second level.
Bury one bottle all the way in the first layer and bury the following bottles more shallowly than the last so you get a spiral incline. Never bury the bottles any more shallowly than the bottleneck or system collapse will ensue! Filling soil around them as you make your next level will provide support. In my case, I used the rotten tree stump as extra structural support. When you get the second layer to your satisfaction, begin planting!
Research your herbs and see what kind of conditions they like to grow in. I planted my sage and rosemary on top to grow large and be well drained followed down the spiral by thyme and mint to the first layer where I planted basil and parsley on the north, full sun side and coriander on the shadier south side.
After planting, mulch well and watch grow!
Harvesting from the tips of many herbs encourages them to grow lateral shoots and become bushy rather than tall and thin. This will give your spiral a robust, filled-out charm.
If you’re really serious, you can drive metal rods into the ground to provide super stable foundations for your inverted bottles. This eliminates chances of them naturally shifting or being removed by inquisitive toddlers!
What a great way to recycle bottles, supply herbs for cooking, and conceal an unsightly, difficult-to-remove tree stump! Go Go Go!
(cc) Hilary Wilson, Permaculture College Australia 2010