To dig or not to dig...

I went to a high school where, in the first year, we had to do Rural Studies.  I’m probably showing my age here, because I suspect that Rural Studies was booted out by the introduction of the National Curriculum, in the late ‘80s, added to the need to build a sports hall over the RS plots. 

Autumn digging

Nearly thirty years ago now, but I can still remember pulling on wellies on damp chilly Monday mornings, collecting tools and trudging outside to undertake our autumn digging, autumnal mists hanging over the playing fields.  Then ensued a convoluted regime of digging trenches, filling them up again, arguing over whose piles of soil belonged to who and whose trenches were the deepest.

These memories all came flooding back recently, when we were required to undertake ‘double digging’ as part of our RHS level 2 practical certificate.  Double digging RHS-style involves digging over a whole plot, trench by trench, removing top soil, working the subsoil in situ, replacing the topsoil… Check out the RHS website here, for the numerous steps in the process.

Do you really need to double-dig?

As far as I’m concerned, my personal view is - only double-dig if you need to tick a box on your RHS assessment.  It’s time-consuming and labour intensive (particularly on a compacted clay subsoil, as at Cheadle College).  It’s perhaps a good opportunity to work in organic matter for new plots and seriously compacted soils, or, as in the case at Cheadle, to add lime to help break up the solid clay subsoil.  But double digging and exposing the subsoil more than once every five years can destroy the soil structure and exacerbate compaction problems. So what could be done instead?

The no-dig alternative

These days, Charles Dowding’s ‘no-dig’ approach is very much in vogue.  Instead of working the soil, he advocates for just the annual addition of 3-4cm layers of organic matter such as home-made or purchased compost or well-rotted manure every autumn.  Disturbance to the soil itself is kept to an absolute minimum. 

This means that there is no disruption to earthworms and other beneficial soil organisms.  Weed seeds are not exposed to the light they need to germinate so weed levels are lower.  On the other hand, one counter-argument to ‘no-dig’ suggests that continual additions of organic matter without working the soil will eventually lead to its compaction.

So which way to go?  I have to concede that Charles’ approach is very compelling; organic, good yields, less weeds, less labour intensive - as his website demonstrates.  But I’m afraid that I just can’t help myself; I love to stick a fork in every now and again, break the topsoil up a bit, and mix in some compost.  Perhaps I’ll just select my favourite parts of both approaches.

Coming next - Naturalising crocus bulbs