As many of you know, I live in an area where there will never be a shortage of sandy soils. While many view our sandy soils as some kind of curse that nature has inflicted upon us and stand in the garden shaking their fist at the earth, having sandy soils means that we can easily install native gardens as well as regenerate our soils without having to break down clay. There is no such thing as a complete soil so the regeneration that sandy soils need isn’t really a problem if we get the ingredients and amendments right for the plants we want to grow. In order to grow non-native vegetables, I have had to build up my soil in order support the needs of a range of foods originating from different countries.
I make a conscious attempt to utilise everything that is readily available and can get my soil encrusted hands on for free, before I even consider purchasing anything. Not only have I found this approach more sustainable, but also more natural and a hell of a lot cheaper! This has included using material such as logs, branches, twigs, leaves, grass, palm fronds, cardboard, newspapers, waste from juice bars or cafes, and of course my own kitchen waste; while the list of materials I have purchased for an affordable price includes hay, pea straw, lucerne, various manures, heat treated composts and powdered soil additives.
I have used many different ways to build up my soil, depending on what I had available to me at the time at either little to no cost. Here are 4 of my favourites.
The quickest and easiest way I have used to build up my garden beds is one of the methods that I am currently using for my Winter bed - which is the Charles Dowding no-dig method. All that is needed is cardboard, which is easily sourced for free (try friends, family, local shops and save any from flat pack furniture), and compost. I have used a mix of my own and bought compost, well rotted manure and even mushroom compost. Although I pulled up the grass on the site I used, (yes, I'm kicking myself now!) cardboard and compost can be placed directly on grass if you have enough cardboard to suppress it's growth. 2-3 layers of thick cardboard should be fine.
Compost can be bought in bags or purchased from soil companies. Fresh manures can also be bought and then composted at home, and are often available at little to no cost - try farms and those who have herbivorous animals at home, or sites like Gumtree. If you're lucky enough, you'll even find a local Facebook group where manure is posted for free.
This no-dig method is very easy .
Step 1. Make sure your site is clear of debris etc.
Step 2. Lay down a few of layers of cardboard.
Step 3. Cover with compost at least 30 cm high.
Step 4. Plant!
Another method I quite liked, despite the hard work, was Hugelkultur, it literally translates to 'Hill Mound'. This involves digging a small trench, filling it with logs, branches, twigs, green leaves, dried grass, dried leaves, then topping with sod if you have it (the grass you dug from the trench, turned upside down) This requires that you grow plants suited to the soil you remove when digging the trench, or use a compost or additional additives as the last layer, to change the soil type to suit what you wish you grow. I grow Warrigal Greens/ Native Spinach on a small Hugelkultur in my front yard, using the original soil and some compost.
Step 1: Dig a trench.
Step 2: Clear any debris or roots.
Step 3: Collect and organise wood and other organic materials by thickness. The wood available to us was some old Jarrah firewood of different sizes, some Geraldton Wax branches and some driftwood. I even used wood that is burnt to encourage strong roots.
Step 4: Begin piling the wood and other organic material by laying the logs in the trench. You can do however many layers you have. Place the branches on top of the logs. Lay and begin to pile the sticks for the next layer. Then on go the twigs and grasses. We have plenty place of leaf mold all year round, so we added that on the pile. As you stack the materials, try to form a hill mound or a slightly triangular shape with a gentle point/slight plateau.
Step 5: Add the soil dug from the trench onto the pile. If you have sand like I and most everyone in Western Australia does, add plenty of compost and even some manure as per your plants requirements.
Step 6: Add a layer of mulch then plant and/or sow seeds.
A more sustainable way to create soil is using all the materials from your garden and neighbourhood. I found a combination of branches, twigs, leaves, and also used compost from my bins and mulch. This is an especially handy method if you have a mass of plant waste from your or other's gardens. I started by laying out branches, then twigs, leaves, green waste and veg scraps, bought compost and my own compost complete teeming with life. If you want to plant seedlings in the beds straight away, pockets of compost can be made and your seedlings popped in. Over time the lower layers of these beds will rot and settle down, which is why it is important that the piles be at least 50 cm, if you are using frames they also need to be overfilled. Under filling then settling results in a lack of light for the seedlings, who will reach further in order to get the sun they need to grow. This creates spindly plants with long weak stems that can't support the upper part of the plant. The stems will either snap or the whole plant bend over, exposing the roots and/or causing your precious vegetables to be slowly ripped from the ground, eventually falling right over and dying. So, be sure to put on as much materials as you can, making a gentle mound in the centre.
Lasagna garden beds are another no hassle, no dig way to build up your soil. This simply uses straws and manures (carbon and nitrogen) stacked up like a giant outdoor lasagna, topped with compost and left to break down into lovely, rich, crumbly soil. To speed up the and maintain life in the soil, I normally add accelerators and feed the soil with a liquid fertiliser weekly or at least fortnightly. Again if want to plant seedlings in the bed straight away, pockets of compost can be made and your seedlings planted the same day.
This bed is currently breaking down with the Winter rains providing plenty of water.
I hope you have found a method here that you can use in your gardens. Autumn is the perfect time to build and improve upon your soil, letting it break down over the Winter months.