Looking back at my Twitter feed from a year ago today, the theme is no-dig raised beds, or as they are known on the other side of the Atlantic, no-till raised beds.

A quick no-dig raised bed vegetable garden from scratch

Just to clarify, a no-dig garden doesn’t rely on raised beds, it simply means, you choose not to dig, till or plough the earth. In this case, a couple of factors dictated that a raised bed is probably the best approach to establishing a vegetable garden: heavily compacted soil that leeches lime, plus possible issues planting delicate veg near olive trees. A no-dig raised bed vegetable garden it is.

In its simplest form, a no-dig garden is created by literally laying thick cardboard onto grass, meadow, soil, or in this case densely compacted clay, and building up a raised bed of soil on top of the cardboard. The cardboard will kill most weeds from below and, assuming your bed of soil is suitable, gives you an instant bed to plant into.

If you have access to municipal compost or a plentiful supply of manure on your land, it would be silly not to kick start the beds with a bang. But I took the approach that if you don’t have trailers and generous farmers, nor loads of money to throw at a new veg garden, how can you get going? So the raised beds above consist of cardboard, a few inches of topsoil, bedding from 8 chickens and regular chopping and dropping of veg.

Getting started

Make beds in the autumn. For the first crop I aim to plant fava beans, a prolific nitrogen-fixing winter crop that grows unattended, and makes any beginner gardener feel like a hero. All the while I have been adding whatever organic matter is lying around, topped off mostly with straw for mulch. And patience has played a role too, because in the early days, with little soil biology going on, it can feel a little like getting blood out of a stone.

Why no-dig?

The no-dig approach mimics nature by adding layers of organic matter rather than digging it in manually. If you think about it, every year leaves fall, plants grow and die back. Worms and bugs take that goodness down, process it, naturally turn over the soil and leave nutrients behind. Vast networks of mycelium develop, and there you have yourself living earth with no human intervention.

The moment you take a spade to even the top 2″ of soil, you break the cycle and pretty much return the soil to its state last year, every year. That’s sort of how big ag farmers grow, and every year need more and more inputs to keep production up. That’s hard work and money that I don’t feel like expending. Simply by adding a layer of organic material to the surface, be that compost or green stuff, you keep the natural soil development going and mostly leave Nature to do the work.

No-dig saves backs and health problems!

With 1 in 4 people suffering from back problems, no-dig is just what the doctor ordered for millions of gardeners. And if you steer clear of chemical potions, your no-dig food will be nutrient-rich, which is just what the doctor ordered for all 8 billion of us.

Weeds

This no-dig system doesn’t stop weed seeds from blowing in, of course. Also strong weeds may eventually force their way up through any poor overlaps in the cardboard. But overall, any weeding is really straightforward because most roots start from the the surface and don’t have time or space to truly bury themselves.

A year on, I can honestly say if you keep a heavy mulch going, it takes under 5 minutes a bed every few months, of easy weed plucking.

However, let it slip and leave soil bare, you can easily end up with a raised grass lawn! Bare soil is of course a cardinal sin. Nature doesn’t do bare. If you plant densely, weeds don’t have much of a chance.

Format of no-dig raised bed

This is a topic of constant debate. My raised beds are accessible all the way round, straight ones are 75cm wide, and mostly have no sides. The classic raised bed garden nowadays seems to be a series of wooden-sided boxes. They hold the soil in, can look aesthetically pleasing and are easy to organise. Other materials used are corrugated iron sheeting, terracota tiles, even plastic IPBs sawn in half.

The second construction consideration for a raised bed is height. You need a minimum of 7″/20cms of soil to grow most common or garden veg.

Hugelkultur beds

If you use boxes, you can go about a metre high and lay a hugelkultur base. If you are in a hot climate, probably better to dig down 90cms into the ground and lay a hugelkultur base.

Hugel what? This slow compost system consists of large trunks at the bottom, infilled and layered up with 2″ diameter and ever decreasing ramial branches. You infill any gaps with smaller twigs, animal manure, leaves, soil, whatever organic matter you have, building like a lasagne. Stop when you are at a level to lay your 20cm+ thick growing bed on top. Below your growing bed, the wood decomposes over several years, trapping water and slowly producing fungal rich compost.

This is a good explainer video from Self Sufficient Me.

No-dig, fine, but do I even need a raised bed?

If you have good soil, it makes little sense to build a box on top and put good soil in it. And if you build a raised bed on a plinth for instance, it is a container by any other name. Containers need more water and more inputs than if growing direct into good earth.

In our case, it makes sense to separate the vegetable garden from the earth with cardboard and build our own soil on top. The soil analysis shows we have high alkaline soil and being on the side of a mountain, lime is leeching into the ground all day every day. Whilst native olives, oaks and rosemary, thyme etc don’t mind that, our tomatoes and cabbages certainly do.

If you want to grow veg between olive trees, again, separation from the soil is recommended due to the oleopathic nature of olives. That was a tip given to us by Walter Jehne, a very learned climate scientist and microbiologist who debated this long and hard with Bill Mollison back in the day. (Walter Jehne on soil biology.)

Doesn’t a raised bed need sides to trap water?

As ever, decisions are based on context. From the plants’ point of view, how you deal with sides and edges revolves around the amount of water the bed has to deal with either from above or from irrigation, tempered by temperatures.

We are in zone 8/9 depending if we get snow. In our climate in summer, you are looking at several months of 30-40C+ and reliance on irrigation. Water retention and stopping water loss at the edges is therefore a key issue to resolve here. The simplest way is to have boxed sides. In the winter, we get most of our annual 550mm of rain, and it can get wet. Solid sides trap water and create excessive damp, which is great for slugs and snails but not great for plants. What to do?

I have gone for no sides, but try to plant herbs around the edges to act as a sponge. I also use a lot of mulch, another mammoth and controversial topic, and that seems to manage water for me. Others won’t agree with thick straw in rainy seasons. In other words, neither a system of mulch nor solid sides will be perfect year round, but I know which is financially the most cost effective, and I hope this article gives you a grasp of the potential issues to look out for.

Charles Dowding

No talk of no-dig is complete without a hats off to Charles Dowding, the UK’s Mr No-dig gardening expert. His own market garden is mainly rows of cardboard on top of meadow riddled with bindweed. For beds, he starts with a healthy layer of compost which he dresses 1″ a year to maintain the soil’s fertility. From experience and experiments, he has demonstrated that his no-dig approach generates more food than an equivalent size normal dig garden, and obviously for much less work day-to-day.

He is very generous with his knowledge, and a good citizen on Twitter. His tips certainly help us learners on the front line. And on November 3rd he is launching No-dig Day. If there is no frost before then, I may be still harvesting some no-dig cherry tomatoes!

US Mr No Dig

Jim Kovalevski literally just plants and picks from his no-dig mulched raised beds. From what I can gather, one of his tricks for maintaining soil health is using thousands of seed blocks. In other words, every time he transplants a seedling he is dropping a nutrient bomb into the bed. Do that 25000 times a year and no wonder his beds are bursting with life.

That’s it for now

I hope that this information on No-dig raised beds has spurred you on to set up an instant no-dig vegetable garden. With the cost of food, and the questionable quality on sale from mainstream stores, now is as good a time as any to get going.

And here is a small slice of another no-dig vegetable garden on the property. Testament to a lot of work with the initial set-up, plenty of inputs up front, sweat irrigation, regular potent green teas and generally keeping on top of things. I can’t take any of the credit, but I will get the skinny on the very different line of thought behind this, and share it later.

About us

Just a reminder that our primary mission at Asociación Mas del Puch is to restore biodiversity in the Mediterranean biome. We are a not-for-profit association sharing our findings on how to regenerate a formerly ploughed and modern farmed olive grove. To ensure as ecologically sound an environment as possible, we apply zero chemicals, zero synthetic fossil fuel-based fertilisers. The transformation over 4 years is marked and completely replicable. We hope that readers understand the importance of this work and are motivated to come alongside and support the project either with donations or by spreading the word.