The classic 'no dig' garden is based on the simple principles of composting layers and processes, encouragement of soil micro organisms, particularly worms, and the creation of humus.
© Maria Ciavarella, My Green Garden
No Dig Methods
No Dig gardens are, in effect, composting gardens.
No Dig gardens rely on layers of carbon materials and nitrogen materials. High nitrogen materials, such as manures and blood and bone, break down high carbon materials like straw and newspaper in the presence of good moisture to become compost. More carbon material is required than nitrogen material, which means the nitrogen layers are thinner than the carbon layers. Essentially, in a No Dig bed, the material is what ends up both feeding the plant and what the plant is growing in.
Composting is encouraged by the use of organic materials in layers, the moisture in the garden bed and the use of fertilisers such as animal manure.
A layer of animal manure is placed between every 2nd or 3rd layer of organic material to provide nutrients and aid in the composting.
The fertiliser provides nutrients to inactive materials such as paper, sawdust, and straw to break them down with the aid of micro organisms like fungi, bacteria; and macro organisms such as worms and insect larvae.
Worms play an integral role in no dig gardens, by dragging material from the No Dig garden into the soil underneath, greatly improving the base soil.
Worms can be added to the no-dig bed; or, if your No Dig garden is laid on soil and wetted newspaper, will migrate to your bed anyway.
Image taken from “No-Dig Gardening ” by Allen Gilbert
Basic 'no dig' garden construction
- Select the site. It can be over weedy lawn, poor soil, good soil, or even concrete. On non-permeable surfaces you may want to lay down pebbles, gravel or prunings to allow aeration and drainage. (on concrete, you may want to include drainage pipes).
- Design the garden, work out how large you want it. Make sure the bed is narrow enough for easy picking from either side, by stretching out with your arm. Double this to become the width of the bed.
- Gather your materials, including:
- High nitrogen materials such as animal manures, grass clippings, green weeds, worm castings, blood and bone, organic fertiliser pellets, fish meal, coffee grounds;
High carbon materials include straw, dried leaves, autumn leaves, husks, newspaper, shredded paper, cardboard, telephone books (use them whole as edging or ripped up and mixed with thicker material or manure in a layer);
Edging materials such as edging in recycled timber, sleepers, rocks, corrugated iron, pads of hay bales, concrete blocks, telephone directories, whole bales of straw (if making a large garden).
4. Ensure access to a hose connected to a tap as you need to water layer by layer as you build.
You're now ready to build...
- Put down a base layer of newspaper about 6 sheets thick. If you are building over tall weeds slash them down and leave them in place. Place the newspaper over the flattened weeds. Paper also acts as a weed suppressant. Wet it and keep it down with handfuls of compost as you lay it out.
- Place vegie scraps (if you have any) to attract worms, or a layer of blood and bone to help break down paper.
- Start to add your layers. Add thick layers of carbon-based materials, wetting each layer as you go and then top those with a thinner layer of the high nitrogen materials.
- When you put down the final layer make it of about 10cm of a good, weed free propagation medium such as mature compost or soil and compost. Otherwise create pockets within the top straw layer and fill these with the propagation medium.
- Plant seeds or seedlings into top layer of soil or into pockets if your top layer is straw, then water in with a seaweed fertiliser to encourage root growth. Further applications of seaweed fertiliser throughout the growing cycle will strengthen and make plants more resistant to pests and diseases.