To dig or not to dig, that’s the question. If you’re part of the legion of new vegie gardeners taking up the spade in a quest for the good life, you could be forgiven for wondering who you should believe. The advice seems completely contradictory. Should one take the advice of the no-dig advocates, who argue passionately for the spade to be left in the shed, or is it safest to believe the traditional gardeners, who argue that theirs is a tried and true method refined over hundreds of years? Or is there a third way that finds some common ground between the two extremes?
We’ll get to the answer later, but first, let’s explore what I mean by “no-dig” gardening. The concept has actually been around for decades, just under different names. It began in the1930’s with the Japanese farmer/philosopher/scientist Masanobu Fukuoka, who from 1938 until his death in 2008, experimented with various small scale farming techniques that he collectively referred to as “natural farming”. Fukuoka’s philosophy was based on a simple concept: the farmer should interfere as little as possible with natural processes. Crops could be grown, he argued, without machines, with no prepared fertiliser and no chemicals, yet attain yields equal to or greater than the conventional Japanese farm.
One of the main components of the Fukuoka approach was to use ancient techniques like cover cropping and seed balls in order to totally avoid having to cultivate the soil. Fukuoka’s concept was characterised as “no-till” farming and enthusiastically embraced during subsequent decades by both agricultural scientists and the growing band of farmers interested in natural farming methods. It wasn’t until the late 1970’s though, that a Sydney gardener named Esther Deans applied Fukuoka’s techniques to the domestic backyard.
In two well regarded books, Deans outlined the concept of “no-dig” gardening. Her basic idea was to build garden beds above the soil surface by layering various materials on top of each other like a kind of horticultural lasagne. Layer one is wet newspaper laid on the soil (or lawn) surface to smother weeds and grass. Layer two is straw or lucerne hay. Layer three is organic fertiliser such as pelletised chicken manure, or blood and bone. Layer four is straw. Layer five is manure. Layer six, the top layer, is good quality compost. Each layer is watered progressively as the beds are built.
Anyone who’s done a spot of composting will know what’s going here. When first made, a true no-dig garden is basically a fancy compost heap. A high nitrogen material (manure) combined with a high carbon material (straw) will decompose in the presence of moisture and oxygen, creating a soil-like material (humus) that is okay for growing plants in.
No-dig advocates claim a slew of advantages over traditional techniques. No-dig gardens don’t need to be cultivated, thereby eliminating damage to fragile soil flora and fauna. They are perfect for those who are unable to wield heavy tools. They are more fertile than traditional gardens. They can be made over really poor soil or even solid concrete.
Sounds great, doesn’t it. In practice, no-dig isn’t as simple as it appears, especially long term. As no-dig gardens decompose, they shrink, and need to be constantly topped up with copious quantities of organic matter. When built over a hard pan, serious drainage problems can develop in wet conditions. No dig garden beds need to be either really narrow or modular for ease of access. Then there’s the myth shattering truth that vegetables need to planted, and planting (even sowing) requires some degree of cultivation. There ain’t no such thing as a totally “no dig” vegetable garden.
So in answer to my original question, to dig or not to dig, my approach is to find a middle way. I’ve tried no-dig gardening, and it proved a tricky proposition. Instead, my philosophy is one of minimal till. I believe there are times when a good dig is beneficial for both the health of the garden, and the health of the gardener. While I don’t advocate the old techniques of double digging and annual winter cultivation, I have no qualms about digging in a green manure crop, cultivating the soil as part of my annual crop rotation, or growing carrots in ground worked to a fine tilth.
I suppose what I’m saying is that there’s a case to be made for digging, but with restraint rather than abandon. Before putting spade to soil, I try to use my brain. I ask myself questions, things like: “why massacre earthworms if I don’t have to”; and “do I really need dig this particular bed, or am I blindly following convention”. In gardening, as in life, the real answer is all about finding a healthy sense of balance.
First published in the Toowoomba Chronicle 29th June 2010.
