The Advantages of No-Dig Gardening

Winter digging looms ahead. Well, for some of us, anyway. Personally I never do any. No, the moment I read Gardening without Digging by A Guest, first published in 1949, I was hooked. Mr Guest estimated that, even with the need to produce more compost, No-Dig reduced labour by at least 40%! Lazy? Definitely! But my enthusiasm was boosted by a bad back. Instead of hours lifting and twisting a heavy spade on cold afternoons, I now spread compost in around November and leave it. Simple as that.

I’ve also, on the whole, cut down on weeding. The additional compost is always likely to sprout some weeds, but other weed seeds in the beds aren’t exposed to light because they’re not turned over and therefore I don’t suffer that flush of weeds that digging always seems to bring on.

Why Use the No-Dig Method?

No-Dig gardening has, I think, special appeal to organic gardeners. It focuses on protecting the life in the soil and research backs this up. Not only do worms not get bisected by your spade, but agricultural research has shown that the more often and deeper that soil is disturbed, the fewer and smaller are the worms found in it. With regular compost mulches your worm population will increase.

And we want as many worms as possible. Worms aerate the ground with their burrows (which also form channels for roots and rainfall), and produce casts that are considerably richer in nutrients than the surrounding soil, partly down to the nitrogen-fixing bacteria found in their guts, which help them transfer a significant amount of nitrogen to the soil from the plant litter that they ingest. They’re surprisingly fast too. By the time I come to sow in spring, worms have incorporated much of the autumn compost I spread on top into the ground below.

Digging also tears up mycorrhiza - invisible fungus-like networks that live symbiotically with plants, benefiting the roots. Mycorrhiza grow slowly at only 15-20 cms (6-8 ins) a year. Digging destroys the networks, preventing them from establishing themselves widely, thus reducing some plants’ ability to access nutrients and resist pests and drought.

Of course, all that compost also improves water retention. According to the website of the Good Gardeners Association (an organisation dedicated to No-Dig gardening), a layer of compost will absorb 69% of rainfall. Dug into the soil, it can’t expand enough to do this. I’ve certainly found that, even in the periods of hot, dry weather this year, I didn’t have to rush out with the hose each day as the raised beds (often criticised for drying out quickly) retained moisture below the surface in the plentiful organic matter.

No-Dig Gardening in Practice

So if you fancy a change, now would be a good time to prepare. If your soil is compacted, this means one last dig over to loosen it up before spreading compost (and don’t spread compost when the ground is frozen). On a plot without raised vegetable beds, decide where you want your paths and stick to them, spreading the compost between them.

You might decide on raised beds. They aren’t necessary to No-Dig, but I think they’re easier to handle: the compost can’t spread out of situ, and as other people won’t be tempted to tread on them, the soil doesn’t get compacted.

It’s also extremely unlikely that you’ve produced anything like the amount of compost you’ll need (possibly you never will) so you’ll need to find a supplier and order some in (a lot easier than collecting from the garden centre). I top up my beds with a mix of home-made compost and bought-in well-rotted stable manure.

Above all, you must keep it up. No spreading a thick blanket of compost with a sigh of satisfaction and thinking you won’t need to do it again for two or three years. Without fail, it must be added once a year, to a depth of about 5 cms (2½ ins), though if you add more during the year and your soil is in good condition you’ll probably get away with less at this point. You can also add compost whenever you think it’s needed; I generally add it during the summer wherever veggies have been harvested.

If you do leave it too late to spread compost in the autumn, all is not lost. It’s perfectly possible to sow straight into a layer of compost, so long as it’s not too rough for small seeds. In the first year of the No-Dig demonstration garden at Capel Manor College, seed was sown into three inches of compost laid straight on to grass. They had a super harvest.

Finally, perennial weeds are often cited as a reason against No-Dig gardening and I have plenty – ground elder invades my flower beds every year. These beds are sadly neglected – I just don’t have the time to dig them or spread compost widely. However, in areas where the beds have been properly mulched over time, the ground elder roots run closer to the surface. Teasing the white strings out of the loose, friable soil in long, unbroken pieces is deeply satisfying. And if that’s not a reason to change to No-Dig, I don’t know what is!

By Helen Gazeley

Image at top of page courtesy of the Good Gardeners Association