What Are ‘No-Dig’ Beds?
'No-dig' bed at Sizergh Castle, Cumbria
Establish 'no-dig' beds for healthier soil and less labour input
‘No-dig’ means that there is minimal soil disturbance; there is a theory that not digging the soil produces a healthier more productive soil structure. The aims of the technique are to produce an undisturbed community of soil fauna, bacteria and fungi which will form symbiotic relationships with the plants and lead to a healthier crop, with very little input in the form of artificial fertilisers. A heavy clay soil may take 2 – 3 years before it is working effectively.
These beds have fewer weeds than those which are regularly dug over as disturbing the soil brings dormant seeds to the surface. You may have to dig the bed initially to remove any pernicious weeds or you can cover them with sheets of cardboard or a light excluding membrane covered with a layer of mulch, for the first year. You can plant vegetables which need plenty of space, such as pumpkins, squash or courgettes through this layer, but will have to make sure that the weeds cannot get through the planting hole.
The first thing to do is form the beds; they do not need wooden sides. Just form mounds of earth about 120cm (4’) wide so you don’t need to walk on them. Paths can be left as bare soil; using paving slabs or chipped bark can create a breeding ground for slugs.
Board at Sizergh Castle, Cumbria explaining the principle of 'no-dig' beds
In autumn clear any old vegetation and weeds then cover the mounds with a good layer of garden compost or well-rotted strawy farmyard manure, about 2.5 – 5cm (1 – 2”). This will be broken down over the winter and then will be pulled into the soil by earthworms where it will be broken down by bacteria and fungi. A healthy population of earthworms will aerate the soil and prevent it from becoming compacted and will also ensure that it is well drained.
This technique is probable better suited to planting established young plants rather than to sowing seed, but you can sow seed by laying down lines of seed compost and covering with more compost.
Once the young plants are planted cover the beds with a good layer of mulch, about 5cm (2”); this can be leaf mould, garden compost, composted green waste, spent mushroom compost or straw. Mulching the beds will slow down evaporation so remember to water well before applying the mulch.
Care must be taken to thoroughly water the mounds as it can just run off, depending upon the type of mulch used. Also keep on top of the weeding; either by hand pulling or lightly hoeing. Once the system has become established there should be no need to use any kind of artificial fertiliser but a dressing of dried seaweed or volcanic dust will be beneficial as they top up the essential minerals and trace elements.