How Deep To Dig Garden Bed

One of the many things I love about hosting this podcast series is the opportunity to talk about a shared love of gardening with experts from various fields and gardeners who come from different experiences and methodologies. This week was all of that and more, because this week, I had the distinct pleasure of speaking with British gardening legend and the guru of no-dig gardening, Charles Dowding.

Not only do Charles and I share a love of gardening – we have a shared love of teaching too. Encouraging new gardeners to give it a go – and experienced gardeners to try a new approach – is something that inspires and motivates Charles and me every day.

So, it was particularly fun to spend time discussing all of that and to hear which of his experiences and approaches are similar, or different, from my own.

Charles and his garden are featured often in magazines and newspaper articles as well as appearances on the BBC. (photo: Courtesy of Charles Dowding)

Meet Charles Dowding

If you aren't already familiar with Charles, allow me to introduce you. He's been gardening for nearly 40 years and a beloved expert in the field for most of that time in his home territory of Great Britain. His influence stretches across the globe, including a strong presence on social media, several books, and appearances on the BBC.

Charles grew up on a dairy farm, but during his college years, he read a book by Australian philosopher, Peter Singer, which inspired him to become a vegetarian. It also led him to think differently about all food. So when he began to develop his 1.5 acre landscape shortly after graduating from Cambridge University, his principles of appreciating all forms of life extended into the garden there too.

A self-taught gardener, Charles didn't graduate in horticulture. He credits his lack of formal gardening education for allowing him to view things differently than the traditional norms. One big example of that is his interest in gardening organically.

At the time, organic gardening wasn't popular in Great Britain. Charles discovered the UK's Soil Association, but the focus of that organization revolved around the impacts of synthetic chemicals. With his keen respect for life, it struck Charles as odd that there wasn't much awareness or discussion around life within the soil.

There was a small group of like-minded organic gardeners, and through them and his natural love of reading, Charles discovered books by some organic garden pioneers – including J. Arthur Bowers, who employed and wrote about a no-dig garden approach in the 1940s.

His first year on his 1.5 acre property, Charles took the usual advice and rotovated (the British term for tilled) some of the stony, brushy soil to create his garden beds. That season, his reading led him to the works of Ruth Stout – the American gardener who pioneered the no till gardening method in the U.S. Her approach resonated with Charles, and he's never looked back.

Homeacres, located in southwestern England, sits on less than a single acre, but nearly a third of that is cultivated for crop production. (photo: Charles Dowding)

He's now renowned for his no-dig garden. It's a method he teaches and continues to put to the test season after season.

These days, Charles gardens in southwest England on a three-quarter acre property he calls Homeacres. He describes the climate there as "temperate oceanic." It's along the latitude of the Canadian Northwest, but the Gulf Stream brings warmer air to Charles' region. Temperatures don't dip much below freezing in the winter, and summers are humid but tend to remain under 80 degrees Fahrenheit. Light intensity tends to be low throughout most of the year.

Nearly all of the beds at Homeacres are in-ground, and the garden produces over 20,000 pounds of produce each year. What does Charles do with all that food? He sells it to a local market and a large restaurant in the area. They purchase his organically-raised crops all year long.

To say that Charles keeps busy would definitely be an understatement. Along with managing the garden, he also writes often and shares his knowledge with other gardeners directly through his teaching courses.

Between Charles and his garden help, maintaining Homeacres crops and landscape beds takes about 70 hours each week from April through early November. The operation slows down a bit through the winter, when Charles estimates their work hours drop to approximately half that number.

He credits his no-dig approach as the reason Homeacres is largely weed-free and, so, doesn't take far longer to maintain.

Charles is a market gardener. He sells most of what he grows. His goal is to grow enough produce that his two area clients receive an abundance all year long. (photo: Johannes Pelleter)

The No-Dig Garden

Charles refers to his garden as "no-dig." I refer to mine as "no-till." How are those methodologies different? They are, in essence, the same principle – just different terminology.

No matter what you call it, these principles focus on the benefit of not disrupting the life within the soil. There are billions of microorganisms, known as the soil food web, down there; and they create microscopic pathways to transport water and nutrients. It's those pathways which increase soil's ability to drain excess water, while also retaining a proper moisture level.

Like me, Charles' garden is located in an area of heavy clay soil. We have both improved our soil – not with tilling – but by adding organic amendments, like compost. The organic materials feed the soil and the microorganisms which have a natural ability to increase permeability of clay soil.

Charles compares soil to an organism and, in his experience, a happy organism is less likely to foster weeds. He is so dedicated to a no-dig approach that he cringes when having to harvest root crops, like potatoes. Charles opts not to dig up tap-rooted weeds either. He believes that any disturbance forces soil into a recovery period, which upsets a natural balance, and that lack of balance creates an opportunity for weeds to take hold.

The proof really is in the results. Even the pathways in Charles' garden, worn by foot traffic and the wheels of garden carts and wheelbarrows, drain well during periods of heavy rain and are largely weed free.

He's often asked if he uses a liner under the paths to block weeds. There are no liners at Homeacres. Instead, it's all about soil health. His first year in the garden, Charles mulched paths heavily over a layer of cardboard, but he hasn't mulched since then. Each year, he adds a thin layer of compost over his paths in fall and believes the result is soil that is so healthy it creates an environment that isn't conducive to weeds.

Most of the beds at Homeacres are in-ground, and Charles keeps them occupied with intensive planting most of the year. (photo: Charles Dowding)

I'm a big believer in maintaining a good layer of mulch over all exposed areas of the soil – including my pathways. It protects the surface to retain moisture and prevent erosion. It blocks the light from reaching any weed seeds waiting in the soil for their opportunity to germinate. Plus, natural mulch slowly breaks down to provide more nutrients and organic matter for the soil food web.

Charles, on the other hand, takes a different approach. Slugs are a big problem in his corner of the world, and he found that mulch promoted more slug pressure. So now, he mulches heavily just once – during the first year in a new garden – but he never mulches again. Instead, he amends every year with a layer of compost.

The compost sits on the soil surface to act like a layer of mulch until the soil food web works it into the surface. As a result, Charles does have some weeds which pop up in spring – those that blow in on the wind, for example – but for the most part, there aren't many weeds to be found at Homeacres.

It just goes to show you that everyone's climate and situation is unique, so observe what takes place in your garden and apply the methods that make the most sense for your conditions. What works for someone else might not work for your garden.

Putting It to the Test

Charles puts the no-dig method to the test to really see how it measures up. Each year, he grows trial crops in side-by-side beds. One bed he maintains traditionally – by working compost into the surface. The other bed is no-dig – adding a layer of compost over the surface and allowing the soil food web to do the rest. He plants the same crops in each bed to track progress.

Throughout the season, Charles documents the growth, health and production of the trial beds – taking precise measurements and weights. He's in his seventh year of trialing at Homeacres, in addition to trialing  for six years in his previous garden. Throughout that time, the no-dig beds have had fewer mildew problems and slug damage than in the traditional "dig" beds just a foot or two away.

Always experimenting, Charles keeps detailed records of the progress and production of his trial beds. (image: Charles Dowding)

The no-dig beds tend to produce more too. Although the crops vary from year to year, the no-dig beds average 6% better production by weight, and the crop quality tends to be noticeably better than that of the "dig" bed.

This year, Charles is experimenting with another trial he calls the "strip trial." In one strip of the garden, he used a pitchfork to turn over the soil in the strip and work in compost. In a strip nearby, the compost was left in a layer on the surface. In a third strip, a different type of compost was left in a layer on the surface.

So far, the forked strip has produced 5% less in crop weight than either of the no-dig strips.

So, the no-dig approach isn't just saving him time when he adds amendments, it's also producing as well (or better) and costing him less time in pest and disease management too. After 13 years, it's hard to argue with those consistent results.

Here at the GardenFarm™, I amend my raised beds by placing a layer of compost over the surface, and I very lightly scratch it into the surface. However, I've also made it a practice every few years to plunge the tines of a broadfork into the soil and wiggle the handle just a bit. It creates holes to aerate the bed and introduce more oxygen under the surface.

After hearing Charles describe the results he's seeing from the undisturbed beds, I may follow suit and discontinue my broadfork aeration approach. With five acres to tend to, I would be more than happy to use that time elsewhere.

For the past 13 years, Charles has incorporated trial beds into his gardens. The bed on the left has had compost worked (dug) into the soil. On the right, compost was simply left in a layer on the surface of the no-dig bed. In April, some of the vegetables in the no-dig bed already show signs of better health. (photo: Charles Dowding)

A Busy Garden that Bucks Tradition

With two large market clients and a never-ending curiosity, Charles is planting intensively throughout most of the year. He's always looking for gaps between larger crops where he might insert a few seedlings and get a jump start on the next harvest.

He starts 95% of what he grows in his large greenhouse, so that those plants can be growing while the previous crops in the garden are finishing. In fact, the only seeds he sows directly into the beds are carrots, parsnips, garlic, and potatoes. Everything else begins life in seed trays.  Charles never draws out a formal garden plan. He works by instinct, experience and opportunity – making use of interplanting and succession planting to ensure he's got plenty of produce to provide to his customers.

His beds are so busy producing that Charles never plants a cover crop. One of the benefits of a cover crop is to protect the soil surface, but the beds of Homeacres are nearly always packed with intensively-planted edible crops. So, the soil is being protected by a dense canopy of plants.

The second benefit from a cover crop is its ability to replenish soil nutrients, but Charles has found that the no dig approach and a yearly amendment with compost keeps his soil rich without the need for cover crop nutrients.

In fact, he says it has become a crusade for him to seek out simpler ways to garden. To that end, he doesn't rotate his crops between beds either. He practices what the Japanese refer to as Natural Agriculture or Continual Cropping, which is nothing more than continuing to plant in the same location year after year.

Crop rotation is recommended as a method to prevent soil-borne plant diseases. Since certain plants are susceptible to specific pathogens, moving those plants from bed to bed starves the pathogen of the food source they require to thrive.

The same trial beds are seen here in August with a second planting of crops. Why spend time digging in amendments when you can see such gorgeous results from the no-dig approach bed on the right. (photo: Charles Dowding)

Always one to put tradition to the test, Charles is banking on a different philosophy. His thought is that, when the microbes in a bed of soil become accustomed to interacting with the roots of certain plants, they will become more efficient at feeding and protecting that type of plant.

Well for the past five years, he has planted a row of fava beans in the same location to test his theory. This year, the plants are the healthiest he's seen so far. Is that proof that crop rotation isn't necessary? In some circumstances, maybe. That said, Charles starts his fava beans from seed he has saved from earlier crops, and he believes that makes a difference in how they interact with the soil of the bed.

What about taking a soil test? Well, Charles bucks that standard horticultural advice too. He never tests his soil. He believes he can tell what his soil needs by observing the health of his plants. He also feels that soil pH has less of an impact on the health of most plants than is traditionally thought. Although most edible plants prefer a pH near neutral (6.5 to 7.0), the pH of the soil in Charles' previous garden was around 8.0. However, he reports that he didn't experience any noticeable problems with plant health or production. He believes that the true test is how healthy and productive your plants are.

Winters are mild, but the cool temperatures extend well into spring – as seen here in this frosty photo taken in early April. (photo: Charles Dowding)

Getting Started

By now this no-dig/no-till approach may sound appealing, but you have new beds to install and existing sod or other plant material to contend with. What to do? Well, don't break out the tiller. It will only bring dormant weeds to the surface, and it will break up the structure that your personal soil food web has been diligently building.

All you need to do is cover the area of your future bed with a layer of cardboard – directly over the existing plant material. You may need to mow the grass or shear tall weeds, but the cardboard goes right over the top. Next, add a heavy layer of compost. Charles likes to use about 6" the first year he is building a new bed.

How long do you have to wait before you start planting? Good news – you don't. You can sow seeds or seedlings directly into the compost. By the time their roots extend down to the cardboard layer, that material will have softened enough that the roots can push right through it into the soil.

Next season, the bed will be ready to plant with a new crop. No digging or tilling required. As you amend with compost or other organic nutrients and add a layer of mulch (as long as you aren't struggling with slugs, like Charles), you'll be feeding the soil food web, and your soil will get better and better every year.

All that said, rocky soil will need a little more elbow grease. The microbes of the soil food web are powerful, but they won't break down rock – at least not in a lifetime. So if the volume of rocks in your native soil prevents you from creating a great growing environment, an initial tilling may be the only reasonable way to improve conditions.

Like me, Charles incorporates flowers among his edible crops to draw in more pollinators and other beneficial insects. (photo: Charles Dowding)

Removing the rock can require quite a bit of effort, but once the job is done, there should be no reason to come back and have to till again. From that point on, you can employ a no-dig approach and allow the soil food web to begin building those all-important networks.

Another option if your native soil is rocky – raised beds, of course. By building healthy soil above the natural rocky layer, you can avoid the digging altogether and enjoy as much control over conditions as Mother Nature will allow.

The bacteria, fungi, protozoa – all those microorganisms of the soil food web – will create an environment that is more able to withstand drought too. Their pathways will allow the soil to retain water longer, but the organisms, themselves, are able to seek out precious moisture when necessary. In fact, fungi in the soil food web can work themselves into tiny crevices that plant roots can't reach to draw out latent moisture when conditions are particularly dry. These creatures may be tiny, but they do a lot of work on behalf of our gardens, when we give them the chance.

But Wait – There's More

Would you be surprised if I told you that my talk with Charles ran longer than we had planned? We had so much to talk about that I had to extend this podcast into a two-part series. So, stay tuned for next week's episode.

The greenhouse is used all year long – producing food and providing shelter for seed starting. Seen here is a bounty of food growing and harvested in early August. (photo: Charles Dowding)

In Part Two of this discussion, we dive deeper into the subject of compost. Charles has quite the system, but we are both big believers in keeping things simple. We also talk about pest and disease management, so you won't want to miss that.

You don't want to miss this week's conversation either. Scroll to the top of this page and click the Play icon in the green bar under the page title. Trust me – it will be worth your while.

Links & Resources

Episode 042: Raised Bed Gardening, Pt. 1: Getting Started

Episode 048: The Simple Science Behind Great Gardening, with Lee Reich

Episode 099: Understanding Crop Rotation: The Basics and Beyond, with Jack Algiere

Episode 100: Understanding Cover Crops: The Basics and Beyond, with Jack Algiere

Episode 110: Why Mulch Matters in Every Garden: What You Need to Know

joegardener Video Blog: No-Till Gardening: If You Love Your Soil, Ditch the Tiller

joegardenerTV YouTube: The Basics of Soil pH

joegardener Online Academy: Master Pests, Diseases and Weeds – my newest online course! Just $47 for lifetime access.

joegardener Newsletter

joegardener Facebook

joegardener Facebook Group

joegardener Instagram

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GGWTV YouTube

Charles Dowding

Charles Dowding Courses

Charles Dowding's Veg Journal: Expert no-dig advice, month by month; by Charles Dowding

Charles Dowding's Vegetable Course; by Charles Dowding

Charles Dowding's Vegetable Garden Diary: No Dig, Healthy Soil, Fewer Weeds; by Charles Dowding

How to Create a New Vegetable Garden: Producing a Beautiful and Fruitful Garden from Scratch; by Charles Dowding

How to Grow Winter Vegetables; by Charles Dowding

No Dig Organic Home & Garden: Grow, Cook, Use, and Store Your Harvest; by Charles Dowding and Stephanie Hafferty

Organic Gardening: The Natural No-dig Way; by Charles Dowding

Peter Singer

Soil Association

Soil Cubed – Our podcast episode sponsor and Brand Partner of joegardener.com

Pete and Gerry's Organic Eggs – Podcast episode sponsor and Brand Partner of joegardener.com

How Deep To Dig Garden Bed

Source: https://joegardener.com/podcast/no-dig-gardening-charles-dowding/

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