Lots of gardeners are trying no-dig gardening but what exactly is it and what are the benefits? Let’s have a look at this approach and why it might be a good option.
Growing without tilling or turning the soil is nothing new. You can read A Brief History of No-Dig Gardening here which includes one of my favorite gardeners, Ruth Stout.
What is No-Dig Gardening?
No-dig gardening simply means disturbing existing soil as little as possible.
Each gardener will adapt their no-dig approach depending on their circumstances.
Here is one example.
When starting a new garden bed, instead of digging or tilling the site, the gardener puts layers of cardboard over existing grass lawn or weeds with a layer of compost or some other mulch on top and waters everything. The idea is that over weeks and months the smothered grass or weeds will gradually die off and the cardboard decomposes, leaving a bed ready to plant.
When planting in subsequent years, the existing soil is left as-is and a new layer of compost is added on top to replenish nutrients.
No-dig = disturbing the soil as little as possible.
No-dig doesn’t mean no shovel, spade, or trowel will ever touch your soil.
You’re still going to be digging holes to add plants or bulbs or whatever you are growing, and you may have some other good reason to dig every now and then.
The difference is, unlike more traditional approaches, we don’t dig simply to ‘loosen’ soil, work in amendments, or grind up grass lawn, but instead create new layers on top.
While the outcomes of dig versus no-dig growing may be similar—either way can produce a thriving garden—there are some advantages to no-dig you might like.
Contents
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No-Dig Gardening Pros and Cons
Pros
Digging May Not Be Necessary
Good news! You may be able to grow just fine without digging.
And this may be the only reason you need to try it.
Some people turn or till their vegetable beds every single year.
With no-dig, if it’s an established bed, we forgo that step entirely and just add compost or composted manure to the surface and add our plants or seeds as usual.
I have neighbors who use a rototiller every single year on their large veggie bed, deeply grinding up the soil before planting. It’s a family tradition passed through a few generations.
But imagine if you could just skip that step and get the same harvest? And what if multitudes of gardeners all skipped that step? It would not only save time but offers possible ecological advantages depending on the machinery and fuel involved.
No-Dig Gardening Videos
Comparable Yields
In terms of yields, there is no published research indicating whether dig or no-dig is better in-home gardens. Just about all research on this topic (and many garden topics) focuses on agricultural settings, so any findings are not readily translated into the home garden setting.
Anecdotally, Charles Dowding has been showing results of his vegetable garden trials for years. It’s not really scientific because it doesn’t have the controls and other experimental design elements we’d need to see, but there are some interesting results.
According to the analysis on Charles Dowding’s website, the dig and no-dig gardens didn’t show any significant differences for yields.
Some vegetables did show differences in some years, with a better yield in the no-dig garden, but there’s not enough data to come to any real conclusions, other than there hasn’t been any decline in yields with using a no-dig approach.
So, you’re not going to lose anything, as far as yields go. It would be nice, someday, to have a real study done, but it hasn’t happened yet.
But again, if you can get the same results while skipping the tilling or digging, why not?
Related: What Does it Mean to “Garden Organically”?
Minimal Disruption to Existing Soil Structures
Here’s the idea.
We used to think of soil as, well, just kind of random dirt with no thought about the importance of soil structure and biota. We just knew some dirt seemed better than others.
But soil is much more complex than that.
Soil structure is comprised of aggregates of minerals and organic bits with pore spaces.
Within there, biota like earthworms, fungi, bacteria, nematodes, other microorganisms, and insects (and more) bring soil to life, helping provide what plants need.
Any time we dig into soil, we’re upsetting all that. We’re disrupting the soil ecosystem—a.k.a. the soil food web—which, with all that digging or turning will need to be re-established over and over again.
So does that actually set us back? Is our garden delayed in any way from digging? There really isn’t any good research on this, but no-dig will let you work with existing soil components, rather than disturbing them.
Prevent Weed Seeds From Germinating
For some of us, one compelling reason not to dig is because there are thousands of weed seeds lurking in our soil. Buried too deep, they do not have the right conditions to germinate.
If we leave them alone, there’s a good chance they’ll just continue to sit there as seeds. But, if we dig and turn that soil, we’re inviting them to germinate.
It may not become a garden horror story if we’re also applying mulch on top, but there’s a good chance any digging and turning can lead to more weeds.
As someone with a lot of weed seeds, this is a compelling reason to avoid digging as much as possible and to make good use of organic mulches.
Cons
No-Dig Isn’t a Quick Fix
Normally we start a garden bed wanting to plant right away but that’s not always possible with a no-dig method.
For a garden with hard, compact soil, switching to no-dig will take time.
You’ll need to smother existing grass or weeds (with a layer of cardboard or something similar) and bring in loads of compost and mulch. The degradation of that cardboard and the work of all those earthworms, microbials, and so on, will take time.
One quicker option is created raised beds instead. They too can be no-dig and more budget-friendly than amending larger garden beds. And, with enough depth, they are ready to plant as soon as they have good compost and soil—any cardboard sitting deep below the compost surface should not interfere with root growth.
It May Take a Lot of Mulch To Get Started
While it sounds great not to have turn, till, or dig soil, in some cases we may be exchanging one big job for another.
No-dig requires the addition of compost or mulch to top dress the garden beds. My rototilling neighbors prefer synthetic fertilizers instead of compost, which comes with various environmental concerns.
Establishing a large no-dig garden could require many yards of mulch at great cost to the management—buying mulch is definitely my most expensive garden expense by far. Not to mention the time and effort to distribute it.
However, I still feel like I’m saving time and energy by not digging because either way I would need to add organic matter to my pathetic (super sandy, unfertile) soil each year.
Others may eye that rototiller and declare it good enough.
Environmental Considerations
As mentioned, there is almost no research into no-dig gardening but a lot of research on no-till farming.
We look for published, peer-reviewed research but most of it covers agricultural settings, not home gardens. Basically, we’re left to pick over the scraps to figure out what, if anything, we should take away as applicable to gardening.
And we certainly don’t want to adopt farming practices that are of questionable value to gardens. That how we ended up with the overuse of fertilizers and pesticides in our gardens to start with.
Conservation Agriculture
No-till farming, and, more broadly, “conservation agriculture” has been, and continues to be widely studied, especially in response to concerns about the degradation of agricultural soils.
While a serious global issue, tropical and subtropical regions have acute problems like soil erosion, lack of water and nutrient availability, all affecting crop yields. It’s been estimated that a third of the Earth’s land surface has been affected by soil degradation to some degree.
In farming, there is hope that no-till methods could have a significant impact in reducing climate change.
There’s more carbon in the soil than in the atmosphere and all above ground plant life combined.
Current estimates are that 20 percent of global carbon dioxide emissions come from the soil, about one-third of the methane emissions and two-thirds of nitrous oxide—all greenhouse gases.
That said, for many farms, switching to no-till would be a drastic change, basically starting the entire business over again. It’s a complex topic with many ramifications and far different than simply choosing not to dig at home.
Could No-Till Farming Help Sequester Carbon?
A few years ago, there was a report suggesting that no-till farming could significantly increase carbon storage in the soil, preventing, or at least delaying it from being released into the atmosphere. This is also the focus of the recent documentary, Kiss the Ground.
The whole topic is still being studied. There’s a lot we don’t know yet, and it looks like the original report was overly optimistic, but scientists are still figuring out what impact no-till might have on carbon sequestration.
So no-till farming may play a crucial role in the future of agriculture—and the world. But, as said, switching is complex and brings whole new issues in agricultural settings.
How much of this is relevant to whether you dig your garden beds is questionable.
Garden soils haven’t experienced the degradation that we’ve seen in agriculture. They’re very different activities with different scales and different effects.
And, while there are things you can do—or avoid—in your garden that contribute to solving larger ecological problems, from a research perspective we don’t yet have evidence on the environmental benefits of no-dig gardening.
But, for us, it’s less work, the results are every bit as good and it’s more in-line with our approach to gardening—working with natural processes as much as possible. And, in our garden, that makes it the best way to go.
Resources
1 Data analysis by Thibaut Olivier (section)
Analysis of the results of Charles Dowding’s no dig trials.
https://charlesdowding.co.uk/no-dig-trial-2019-2020-current-year-at-top/
2 Limited Potential of No-Till Agriculture for Climate Change Mitigation
https://dx.doi.org/10.1038/nclimate2292 (Paywall)
3 Tillage and Soil Carbon Sequestration—What Do We Really Know?
https://dx.doi.org/10.1016/j.agee.2006.05.014 (Paywall)
4 To Till or Not to Till in a Temperate Ecosystem? Implications for Climate Change Mitigation
https://dx.doi.org/10.1088/1748-9326/abe74e (Available)
5 Digging Deeper: A Holistic Perspective of Factors Affecting Soil Organic Carbon Sequestration in Agroecosystems
https://dx.doi.org/10.1111/gcb.14054 (Paywall)
6 Ecosystem Services Provided by the Soil Biota by Lijbert Brussaard
from the book Soil Ecology and Ecosystem Services, edited by Diana H. Wall, 2012
Not available online
~Melissa the Empress of Dirt ♛
