No dig..

As I walk around my village, I see that some of our more industrious citizens are preparing their vegetable beds for the seeding and planting out of what will hopefully become a bountiful yield of scrumptious fruit and veg this year.

‘No dig’ vegetable growing has become the buzzword around allotments and veg patches across the country over the past few years, largely led by Charles Dowding’s YouTube tutorials and well documented experiments on his own plots not too far from here in Shepton Montague, Somerset. 

Indeed, I practised this method, in my own ramshackle kind of way, on my allotment in Bath when I had it, mainly because I was busy in my gardening business and needed to manage my allotment in such a way that it wasn’t knee high in weeds if I couldn’t make it there for the month of May. I had mowed paths, meadow, ornamental flowers and veg growing and I mulched it with pretty much anything that I could find, but the majority of this mulch was grass clippings from the mown paths and those of the grass areas surrounding other allotments, I kept the edge of neighbouring plots neat and collected much material for myself, win win.

It wasn’t until I listened to a podcast by Dr Elaine Ingham from the Soil Food Web though, that I understood to some degree the science of no dig gardening and farming for that matter.

It all has to do with vegetational succession. Primary succession occurs when the land has been laid bare to rock after an event such as scouring by glaciers or volcanic lava flow. There is no organic matter (soil) for plants to grow in, in order for soil to be made up again, a long process of colonisation by lichen, mosses and fungi begins. These break down and make way for other plants such as grasses, annual plants, perennial plants, and later on shrubs, early succession trees, through to old growth forest. This can take many hundreds or thousands of years. 

Another form of vegetational succession is, you won’t be surprised to hear, secondary succession. This occurs when a catastrophic event disturbs the existing ecosystem, stripping the land of all or most of its vegetation, but the soil containing a seed bank and microorganisms, to some degree remains. A typical example of this might be a forest fire or flood but could also be a ploughed field or dug vegetable plot. Obviously with the soil already present, secondary succession is a much faster process than primary succession, but it still requires the rebuilding of the above and below ground ecosystems. 

Good soil for growing vegetables has a high content of beneficial microorganisms such as protozoa, nematodes, bacteria and fungi. These have a mutualistic relationship with plants, the plants releasing sugars called exudates, each one a different flavour that the relevant microorganism wants and in return the plant asks for a different mineral needed for itself. These minerals such as the nitrogen, phosphorus and potassium (NPK) that gardeners often use help the plant to grow and flower in various ways.

There are many more minerals though, such as, iron, zinc, boron, manganese and selenium that help the plant adapt to its growing conditions, fight diseases or insect attack etc. In order for the plant to access these, the plant roots need to extend down into the silt, sand, clay or rock (that make up soil) where the minerals are held. A strawberry root can extend 2m into the ground and many plants reach much further than this, plants in the grass family may extend 8 or 10 metres down. As soil builds over time with the successional breakdown of plants, it develops from very high in bacteria through to, in an old growth forest, being very high in fungus. 

A young soil high in bacteria will grow weeds in profusion, and this is what we tend to create when we dig the soil over. Some vegetables prefer more bacteria and others more fungi but it is the relatively undisturbed building of this soil in the no dig system with both bacteria and fungi, lots of healthy microorganisms and creatures such as arthropods and earthworms that vegetables will grow best in and they will be able to extend their roots further down to access a greater degree of minerals. In terms of our own health, the theory goes: If the plant has all of the nutrition it requires, we will also be getting all the nutrition we require. 

This piece was going to be about the potential health benefits of eating foraged foods and growing perennial veg that has had the time to grow deep roots, but I’ve gone on too long already, so we’ll have to draw our own conclusions on that. 

Anyway, whatever we’re doing in the garden, I hope that it keeps us fit, breathing fresh air and feeling the sun, on the occasions it deigns to make an appearance, on our faces! Happy gardening.

Photo by Steven Weeks