So how does no dig gardening work?
This was the question I put to our friend Ed, a long standing convert to the 'no dig' method, who hasn't tilled or dug his garden for years.
This is what he said:
"Put simply, no dig gardening is a way of replicating nature. In a natural environment the soil isn't dug over every year nor is it left bare of cover. Instead bare patches of earth are rapidly colonised by a succession of plants which live, die and decay in a constant cycle.
Earthworms drag the plant litter down into the soil, digging and aerating the soil as they do so. This aids drainage and creates a beneficial environment for a whole host of other soil organisms including bacteria and fungi.
The soil organisms feed on the plant remains, breaking them down and releasing nutrients that in turn feed the growing plants. Grazing animals feed on the growing plants then return the waste to the soil as manure, and so on... The whole cyclical system supports a self sustaining soil food web.
When we as gardeners intervene in this natural process by tilling and digging, we break the cycle and can cause untold damage to the soil."
"Well the irony is that the problems that digging is supposed to solve, are the very problems caused by digging.
Take soil compaction, for example. Traditionalists recommend regular digging to break up compaction but one of the causes of compaction is walking about on the soil and squashing it, which is what you do when you dig.
Digging to incorporate organic material is also supposed to improve soil structure, but the reality is that you disturb the delicate balance within the soil layers and harm the organisms within the soil.
Organic matter buried deep within the soil cannot be broken down because there isn't enough oxygen and, in any case, most of the vital work of the soil fauna occurs in the top few inches of soil - which you've just turned upside down and buried.Digging doesn't work as method of controlling weeds, either. All that happens is that you turn over a load of dormant weed seeds that have been lying in the soil just waiting for a bit of light to trigger growth."
"Stop digging and rotovating and protect the soil at all times by a combination of living plant growth and sheet mulches (layers of organic material applied on top of the soil surface).
The mulches absorb and hold water in the same way as a sponge. This prevents erosion from surface runoff and encourages the formation of a healthy population of soil organisms.
One of the most important of these soil organisms are the mycorrhizae: tiny fungi that live on the roots of plants. The plants provide them with nutrients and in return they provide the plants with substances that increase the uptake of water and nutrients, enhance root growth and promote resistance to disease. How cool is that?
Bare soil is also an open invitation and will rapidly be colonised by plants that you, the gardener, don't want - weeds in other words. Keeping the soil between your plants covered by mulch helps to prevent this.
That's the theory, but if you don't want to take my word for it, you can easily make your own small no dig vegetable garden and put it to the test!"
You can find more information on the ideas behind no dig gardening at No Till Gardening: Too Good to be True?
Ready to try no dig gardening for yourself? Follow me as I give the the lowdown on starting my very first no dig garden!