Episode 198. First Principles: The No-Dig Raised Bed Garden

This is the World Organic News for the week ending 13th of January 2020.

Jon Moore reporting!

Decarbonise the air, recarbonise the soil!

This week I am drawn to first principles. A new decade, a new start, perhaps or a new decade, refresh our thinking.

So let’s get to it.

What are raised beds?

A raised garden bed is one where the growing area is lifted above the surrounding soil. This can be anything from 10cm (4 inches) to a metre (3 feet). The material used also varies from straight compost to mixture of materials layered one upon the other. I would avoid mixing these layers. Mixing soil layers is not a natural process, by and large. Nature layers, humans blend, is a good rule of thumb. The idea behind this entire website is to mimic nature as much as possible rather than repeat the practices that got us to where we are.

Why?

The first two and most obvious reasons for going to the trouble of building a raised bed are: no digging and no weeds. These are reason enough for me and maybe you too. The benefits are profound. By not digging we do not move weed seeds to the surface, we allow the structures in the soil to grow and strengthen and we mimic nature.

Podcast Sidetrack:

Mimicking Nature is a thing we should be more focused upon. Plants have been growing and evolving for about 700 million years. They may have some systems of growth worked out that we would be wise to follow.

I had a case in point of this at work. Once a month a group of previously troubled 18 to 24 year olds drop by the garden at work to pick up skills and provide a boost of labour. In November we were sowing a mixture of about 15 different cultivars into one of the outdoor beds. I ran through my spiel suggesting small seeds, carrots, rocket and so on, just needed to be spread on the surface and the watering in process would bury them sufficiently to place them where they needed to be. One young lass would have nine of it. She scraped the surface of the bed with the hand to “prepare” the seedbed. She then sowed the seed and pressed down on it. I suggested we do half and half on the next bed. She could scrape half the area for the carrots and leave the other untouched. She wasn’t convinced but agreed. Next month when she returned there was no discernable difference between the two halves. A perfect opportunity to discuss Masanobu Fukuoka’s statement: What Less Can I Do?

I’m still not sure if she was convinced but the evidence was there.

End Podcast Sidetrack.

Other benefits of raised beds include better water usage, more biological activity in the soil and the creation of a carbon sink.

Types

There are a few variations available to the gardener. In the processes I use, they all include cardboard as the base level. I used to include newspapers but these are much harder to get hold of these days as newspapers go digital but if you have access to them, use them.

After the base layer your choices come down to a couple of things. The availability of materials is the main constraint. What we are looking to create is a deep litter. Ideally I would fill the bed with compost or vermicompost (earthworm material) and then cover the surface with a protective layer. This can be straw, wood chips or even shredded paper.

Another alternative is to place the wet cardboard then cover it with straw. Open the straw, make a cut in the cardboard and plant seedlings/seeds directly into the soil. This works well but you need to keep an eye on the possibility of weeds sneaking in through the cut in the cardboard. 

Another variation on this uses 75 cm depth (2.5 feet) of straw with potatoes placed directly onto the cardboard. This is a great way to start but requires good garden boundaries. Netting, wooden boards and such like to keep the straw in place. The straw should be thick enough to stop sunlight reaching the spuds and turning them green. Harvest is easy, lift the straw, collect your spuds.

With any of the approaches, the effect is to stop weed seeds from germinating, the space provides a great growing medium for plants and protects the biology of the growing medium from the effects of wind, direct sunlight and rain induced run off.

What Are The Mechanics of Doing This?

This is the simplicity of the system, once you have the materials together.

  1. Soak cardboard for an hour in water.
  2. Select area of lawn, bare earth etc for your raised bed.
  3. Slash any existing lawn and say goodbye to it forever.
  4. Lay the cardboard/newspapers out in the desired shape of your bed.
  5. Cover to a height of 15 to 20 cm 6-8 inches with deep litter.
  6. Water.
  7. Add worms if you have them, at dusk.
  8. Cover with straw, wood chips, shredded paper.
  9. Water.
  10. Next morning plant out with seedlings.

And that’s that. Your raised bed is up and running.

Deep Litter

As mentioned above, deep litter is the growing medium. This can be any of the following:

  1. Compost
    1. This is a simple enough thing, once you understand the principles. I’m thinking a whole show on compost would not be unreasonable.
  1. Vermicompost
    1. This is the material compost worms leave behind after they’ve eaten it.
    2. It usually contains some worm eggs.
    3. It will definitely sweeten your soil.
  1. Animal bedding
    1. The best I’ve ever used was bedding from a couple of dairy goats. It contained urine and droppings as well as dropped food, lucerne hay and their bedding, oaten straw. I cleaned it our every six months as the garden beds were being replanted. The goats were healthy, the gardens amazing.
  1. Layers of Lucerne (Alfalfa) hay, compost, straw
    1. This is your standard lasagna type garden. In a sense I see this as a non digested form of animal bedding. It does rot down nicely but nothing beats the four stomachs of a ruminant when it comes to speed and efficacy of deep litter creation.
  1. Just straw
    1. This is the option for spuds and directly planting through the cardboard. If straw is all you have, then straw is the perfect thing to use. For the spuds, it is perfect too.

I hope that’s help rekindle your passion for no-dig gardening. I’ve a few one square metre no dig garden plans over on World Organic News. I’ll put a link to page in the show notes.

Remember:

Decarbonise the air, recarbonise the soil!

Thank you for listening and I’ll be back next week.  

~~~~

LINKS

World Organic News

email: media@worldorganicnews.com

One Square metre garden plans: HERE

WORLD ORGANIC NEWS No Dig Gardening Book: Click here

2 Replies to “Episode 198. First Principles: The No-Dig Raised Bed Garden”

  1. I’m sorry to disagree with the method, but experience in gardening says differently. As firstly, if you soak the cardboard before putting it down, it’s really hilarious trying to move it into position (been there and done that). I agree that you need to slash any existing lawn and say that that’s the time to select the area and walk around it several times placing the cardboard down and rearranging it a few times dry to get the feel of it. Secondly, about putting worms on deep litter and then covering them with straw, it doesn’t sound good for them. They’re better off being put on after a little while of the bed becoming slightly established. Lastly, seedlings are too small, better to have young plants that are more established and have a good root system. Hope this helps.

    1. Thanks for your comment. I’m sorry you disagree, I’ve made over 150 beds this way and never had much trouble with moving wet cardboard. The worms don’t seem to mind. Also, seeds, seedlings, larger plants, doesn’t seem to make much difference in my experience. In the end, these things are just nuance. The key is raised bed and no digging and I think we can agree on that. 😊

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