The Herb Spiral
An herb spiral is a classic, quintessential Permaculture project. It puts all your most common kitchen herbs in one, easy to reach location. It ensures ideal growing conditions (with correct design) for these plants. Imagine the top 20-30 herbs you would like to grow in your garden. Each plant will need 8-12 inches of growing space minimum. That is a good 20-25 feet of garden length to place along a path.
Now imagine rolling that path into a spiral. Next lets mound up the center of the spiral. We now have a path spiraling from the top center, around the mound, back to the ground. We've only used up about a 5-6 foot circle of space. We can reach all the herbs easily (the ones in the center are raised up making it easier to reach).
We can plant our herbs needing the most sun on the "sun side" (that is going to be the southern side if you are in the northern hemisphere) of the mound. Plants that need more shade can be placed on the "shade side" (north side in the northern hemisphere) of the mound. Water will drain quickly from the top of the mound and the soil will stay moister for longer towards the bottom of the mound, so we can place our more moisture loving herbs towards the bottom.
An irrigation tube/hose can be run up through the middle of the herb spiral to make watering easier. A small sprinkler top can be attached as well.
In the end, we have a large variety of plants in a smaller place which means weed suppression, pest confusion (pests can't find the one plant they are looking for), and variety for us. It means watering and harvesting are easier for us. It means each plant is given its own ideal microclimate to grow and be happy. This is classic Permaculture!
Here are a few design diagrams for those who like diagrams:
Bill Mollison's Herb Spiral
An amazingly detailed and organized Permaculturist's Herb Spiral!
Another example of an Herb Spiral
And for those who want a video... here you go!