As every gardener knows, one of the key things you need if you are going to grow plants is good soil.
When using permaculture this necessity can sometimes be challenged; for example, in very dry or extreme (very dry/very wet) climates such as Mediterranean, some people recommend using no soil at all but instead growing all of your plants in gravel or small pebbles. This technique, suggested by for example Hemenway (1), is known as xeriscaping and might be worth a try if your garden is particularly prone to drought. On the other end of the spectrum, aquaculture is a technique that involves one’s crops being entirely submerged in water, which has been used for centuries in Asia and whose modern proponents include Christenson (2015) (2).
