What to do with our kitchen and garden waste is a continual conundrum for thoughtful gardeners. And how can we best look after our soil to maintain successive healthy crops? For the newbie, it can be more than a can of worms. Kelly Jean from Green Door cuts to the chase with some practical help to keep things clean in your backyard.
One of the unsung heroes on our planet is the thin strip of topsoil that enables us to grow plants to eat. The strip that is currently eroding away at an unsustainable rate. Taking a mere thousand years to create just a few centimeters, I’m sure you understand the importance of looking after it.
What can we do to help look after our patch of topsoil?
One simple way to help put goodness back into our soil and keep it healthy is to add organic matter back into the soil. Compost, Bokashi, inground composters … there are a range of ways you can keep your food scraps and other green waste out of the landfill. This stops it creating other issues and turns it into a very effective soil conditioner.
In the forest, there is a non-stop cycle of plants germinating, growing, dying and decaying. The soil is replenished by plant matter that falls on it and breaks down to become part of the earth again. In our gardens we tend to like things to look ‘tidy’, and much of the fallen plant material is collected up and discarded rather than letting nature take its course. We then rely on manmade fertiliser to replenish the soil that has had the nutrients used up.
How can we leave our soil in better health than we found it?
We utilise compost – man’s replication of the forest floor process. We start the process by stacking up green layers (food scraps, lawn clippings and the like) and brown layers (fallen leaves, egg cartons, shredded paper, coffee grounds, twigs and other woody materials). We keep the stack damp and let the middle of the pile heat up and start breaking down into rich dark humus (the best soil conditioner around).
It is important to turn the mixture regularly to get the outside materials inside and breaking down. This can take anywhere from one to three months, so there is an investment in time and space. If you have plenty of room, a three-bay slatted timber system is an excellent way to have a continuous source of compost in creation and available to use.
The plastic black compost containers with lids are also effective as they heat up the material beautifully. It is harder to turn the material in these containers, however, and the condensation makes the mix quite wet. It is very important to add plenty of dry ‘brown’ material to the layers. The key to successful compost is in the layers – if you don’t put enough brown layer material in, it will turn into a wet stinky mess!
If space is limited, you still have options. The in-ground composter or ‘worm tower’ has a perforated tube that is buried in the garden with a lid on top. You can chop up your food scraps and drop them in the tube and replace the lid. The worms will make their way into the tube and do their magic. Once the tube is full you can pull it out and empty it into the space left by the tube and move it to another spot in the garden.
Bokashi is an indoor system in a completely sealed twolayer bucket that can sit under your sink or somewhere out of the way. You simply chop up your food scraps, pop them in the bin and sprinkle over the Bokashi ‘zing’, which is a mix of microbes and bran to aid in the anaerobic fermentation.
Once the bucket is full, it needs to sit for ten to fourteen days to fully ferment. Once finished, the liquid that has collected in the second layer can be used as plant tonic and the fermented food scraps are put in a trench dug in the garden and left to fully break down. Ideally you need two sets of buckets. One is filled while the other ferments.
The other option is of course a green waste bin. At least the green waste bin is being turned into compost to be used somewhere – even if it isn’t at your place – rather than going into landfill.
What else can we do?
One of the most important things we can do to look after our topsoil is to minimise soil being left exposed to air and wind where it is easily blown away. Nature doesn’t like exposed soil, so it will always work to cover it up – usually in the form of what we regard as weeds.
If we cover up that soil, it will go a long way to minimising the number of weeds in the garden, keeping the topsoil where it should be and keeping in precious soil moisture. These are all good things!
How do we keep the soil covered?
Utilising other organic matter is ideal – any kind of straw, breaking down fallen leaves, sawdust, aged bark chips, compost etc. These will all break down over time and enrich the soil as well, which is a bonus.
Use plants like cover crops or green manure crops such as oats, mustard or lupin. These can be sown in open spaces in the vege garden and be dug in as mulch and a soil conditioner when you need the space again.
Growing a variety of plants in our garden beds rather than creating a monoculture of one plant means you can utilise ground cover to protect the soil under taller growing plants.
Using roll products like jute or coir fibre, or even wool carpet, are good options on building sites or big areas of new planting. The natural fibres let the soil breathe and allow moisture to pass through while they break down over time.
Other options such as weed mats and rocks are less ideal from a soil improvement point of view, but are still helpful at keeping soil protected if that is the only option. Please don’t use black polythene. Soil is a living, breathing thing – sticking a plastic bag over its ‘head’ is never going to end well.
Looking after our precious topsoil is not just a oneoff action. It’s an ongoing process that needs us to be proactive. It took a thousand years to create the soil – let’s be good caretakers and pass it on to our children in better condition than we received it.
