Spiral Hills are one of my favourite growing situations.
This was my very first spiral hill, in 2012 which was the year we moved to our small acreage,so I also gained some experience using grow bags and various containers as you can see in the picture. I was very pleased with the results and was amazed at the abundance of food provided from such a small space. In fact it yielded so much salad food and herbs, that I was able to share with 14 other people along with our household of 3 most of the summer. Since then we have had a hill every summer to grow in and learning from past experiences our yields are higher every year.
Spiral hills are the ideal situation for growing kitchen herbs right outside your door to use throughout the summer season. The plants used were ; romaine lettuce , rainbow swiss chard , multiplier onions , radishes , rosemary , basil , sage , oregano , apple-mint , and nasturtium . Although many people use them for medicinal herbs and flowers or even for your favourite perrenial or annual flower displays.
The hill was approximately 3-3 1/2Feet/1 Meter tall - by - 5 1/2 Feet/close to 2 meters wide not including the stepping stones, just be sure you can reach comfortably to the center of the hill for weeding and harvesting purposes. Being 3 dimensional , the spiral eliminates wasted space for pathways,linear and monoculture planting, and instead promotes polyculture and companion planting opportunities. This design provided 25 linear feet of planting space.
The cone shape provides many ideal growing climates including full sun and dryer soils to shaded cooler and moister areas, as well as shallow and deep-root situations to satisfy a variety of herbs and salad foods. This makes it so much easier to increase the choice of flavours you add to your daily food preparation. If placed close enough to a thermal mass collector, on the North side, like the side of your house or a brick wall the hill will benefit from the slow emission of heat throughout the nights.
After gathering the materials you need, this is a ONE DAY project for 2 PEOPLE.
We collected cardboard, soaker hose, soil, compost, vermiculite, eggshells, used tea, worm castings, coconut coir,bricks, paving bricks,rocks,broken cement pieces as well as some path stones I had laying around. If you want to use less soil make a pile of rocks in the center about 1x2 feet or a bit bigger. I liked creating the more moist and cooler area for some plants at the bottom.