Wednesday, April 03, 2013

No dig gardening

“To dig or not to dig, that is the permaculture question:
Whether ’tis nobler for the mud to suffer
The spades and forks of energetic gardeners
Or to leave alone this sea of microbes …”
William Shakespeare, 17th century gardener.

When trying to explain to someone what perm(anent agri)culture is, one subject that will quickly come up is that of ‘no dig’. Soil is degraded by continued turning: organic matter lost to oxidisation and beneficial microbes and fungus disturbed, even killed. There are, however, very good reasons to dig, such as to decompact the soil and remove perennial weeds.

One aspect trumpeted by enthusiastic practitioners is that permaculture implies reduced effort and so land intended to be bought into cultivation is sheet mulched (with cardboard and straw) and the planting done through holes cut through the mulch. By the end of the season, the grass and weeds are dead, the mulch has decomposed and you have a crop of veggies. That doesn’t deal with compacted soil though and some perennial weeds, such as couch grass, are particularly resistant to this tactic, weaving pale strings of stolons in between the cardboard searching for an opportunity to germinate. 

Our own policy is to double dig first, getting up close and personal with our soil, removing what we don’t like the look of and giving the soil a loosen to at least two spits (length of a spade head) deep. After that, we might dig it again the following winter to remove of any persistent weeds that we didn’t get the first time and then go to no dig thereafter.

We wanted to plant up a little corner at the junction of two fields with three witch hazels of different colours, an edible hazel, a manuka and a load of bulbs to give us some colour at the grey end of winter as it turns to spring. I put my fork in the ground and found it a touch stony. And it was a touch stony to the left, to the right, in fact just about everywhere.

A look at some old photos given to us by the previous owners when they took over this land from retiring farmers shows this area to have been used as a tractor turning area (= compaction) and another neighbour remembered that Roger used to tip a trailer load of gravel each year over this area to stop his tractors getting mired in the mud.

Rather than just digging planting holes for the shrubs and thinking that burying bulbs wouldn’t be easy, we decided to double dig the whole area. All of the gravel you see in the pile came from that small triangle of field; that’s a lot of riddling! I reckon that there’s the best part of a ton there and it will avoid a trip to the sablière the next time I need to mix some concrete. We added home-made compost, raked it level and planted up, then mulched with deciduous woodchip. With the grass-suppressing bulbs and the mulch, we hope that this pretty corner will be very low maintenance from now on.