This style of gardening is well worth doing if you have poor or clay soil, like to garden the easy way without digging or weeding, or only have concrete instead of grass - yes, it will work on top of the hardest surface.
Apart from making gardening easy, the no dig garden is a great way to improve poor soil because it will eventually decompose and can be dug in to the soil that has been enriched beneath it.
I first read about no dig gardening in 1992 when a friend lent me a book written by Esther Dean who pioneered no dig gardening in Sydney, Australia, in the 1970s because her soil was very heavy clay and awful for growing vegetables. My husband and I had not long purchased a property on the Atherton Tableland in North Queensland, Australia, where the soil was excellent but contained a lot of rocks. My first effort at this type of gardening was fairly haphazard because I used what I had on hand but it still produced lovely healthy vegetables and I have been using this method, mainly to make gardening easier, ever since.
I have developed my own style of no dig gardening but it's very much the same as Ms Dean's. It can be quite involved or simple and I use the simple method, which I've described below.
Stack of newspaper or cardboard to suppress the weeds
Bales of pea straw or lucerne hay, or straw. I've used sugar cane mulch this time because although I prefer to use Lucerne it is far too expensive due to the drought and pea straw isn't available in my area.
Sheep or cow manure or any other animal manure
Poultry manure (optional)
Blood and bone (optional)
Step 1. Prepare the ground first by mowing as low down as possible or scrape the weeds off and put them in a plant pot to make weed tea. I had to level my area a little because there was just too much slope.
Step 2. After preparing the ground put down a layer of cardboard or newspaper, that's about 7 sheets thick and wet the newspaper if it’s windy so it doesn’t blow away. When this layer is finished moisten it quite well. It will all begin to break down after the materials are placed on top. I've used cardboard here because I didn't have enough newspaper - both work well.
Step 3. Lay down the first layer of straw. Each layer should be about 15 cm high.
Step 4. Spread manure, a sprinkle of blood and bone and a sprinkle of garden lime over the top – it doesn’t have to be applied thickly - just enough to cover the straw. I used donkey manure because I had it on hand, and poultry manure. Water each layer lightly before laying down the next one.
Repeat steps 3 & 4 three times or less if you don’t have enough ingredients. My garden is made up of three layers of straw and manure.
Step 5. Cover the last (third) layer with about 15 cm of straw. The finished height should be around 60 cm or so. Give it a good watering to stop the straw blowing away and to begin the decomposing process. Give it a water every few days and leave for a couple of weeks before planting any seedlings.
Step 6. Make hollows in the straw and fill with compost. Plant your seedlings in the compost at the recommended distance between each plant and water well.