Talking about composting on BayFM
This week I have been asked if I could talk a bit about composting on my BayFM radio program.
We have mentioned compost a few times. However, it seems its one of those things that people are a bit hesitant about.
I can understand this as it took me a while to really get into composting. Once you get started, and see the benefits, you will wonder why it took you soo long to discover this magic!
Why should I compost?
One of the first questions I get asked is “why should I compost”?
And there are soo many reasons!! Getting free soil. Improving the biology of your soil. Growing fantastic veggies without additional fertiliser! And helping to reduce carbon emissions and lower your impact on the environment.
So let’s look at these in a little more detail.
When you first start gardening, it’s hard to imagine all your garden pruning’s and grass clippings could actually be of benefit to your garden.
They just look like waste right? But put that waste in the right environment and it can quickly change into what gardeners refer to as “black gold”!
That’s because worms and microbes break down this waste material. They return it to the vitamins and minerals that it started out as.
So you get the carbon, nitrogen, phosphorus, magnesium and all those other minerals in a form that can be easily absorbed by your plants!
And this is why you can grow fabulous, healthy veggies using just compost as the fertiliser.
Believe it or not, what you buy as potting mix or compost from your local nursery or big green shed is just fancy (or not so fancy!) compost, with a high price tag!
Reducing carbon emissions
So, how can it reduce your carbon emissions?
By stopping all the green waste and kitchen scraps from going to landfill! This is the most important reason to compost in my opinion!
It’s estimated that between 30-50 percent of the contents of our rubbish bins is organic matter that can be repurposed as compost.
A lot of people don’t realise that when organic matter goes into normal rubbish bins it gets buried along with all the plastics, tissues and other rubbish.
And when it hits landfill it doesn’t have the air and microbes to help it break down naturally.
Instead it breaks down very slowly! And, along the way, it releases methane and other gases associated with climate change.
It has been measured that a normal lettuce when broken down in this manner can take 20 years to decompose.
In a compost bin it takes around 3 months and releases little to no methane gas. This goes for any organic matter.
I think some people get confused about the difference between green waste bins and normal waste bins because they think they all go to the same place i.e. the tip right.
However, when they get to the tip they get treated differently. The contents of the green waste goes off to be composted while the contents of the red bins gets buried.
How do you start composting?
It’s pretty easy, but there are a few simple rules.
Before we start, there are two main types of composting: Hot composting and cold composting.
With hot composting you build a compost heap all at once and leave it to brew. Cold composting you add to the compost heap slowly.
As hot composting takes up quite a lot more space, I am going to focus on cold composting. That’s what most people in the Redlands will be doing.
Composting involves pretty basic chemistry. The kind of stuff you learnt in primary school!
Basically you have some organic material that is rich in carbon, and some that is rich in nitrogen.
Your carbon materials are often called brown material. This includes things like paper, cardboard, branches and twigs, straw and sawdust and dried autumn leaves.
Your nitrogen rich materials (often called green material) are your grass clippings, green leaves and kitchen scraps.
Manures like chook poo and horse poo are also included in the nitrogen pile, even though they are brown in colour, as they are very nutrient dense.
To compost successfully you need a good mix of carbon and nitrogen materials.
You don’t want to aim for a 50:50 mix because the nitrogen materials are a lot more nutrient rich than the carbon materials. A ratio of around 30:70 or 20:80 is a good mix to aim for.
So where are you going to put all this material?
Ideally your compost bin should be located in part shade. You can compost in the sun, but you’ll need to ensure you keep the moisture up to your compost heap.
I recommend you buy or make a compost bin. There are all sorts of commercially available bins including tumbler bins and beehive bins made out of plastic.
Or, even better if you have the space, build compost bays out of recycled timber. You need at least two bays so that one can be brewing while you are building the other compost pile.
You can also create a compost heap using chicken wire or similar to contain the heap.
Of course you could just dig a hole in the ground and bury your waste. However, this can take longer to break down and may attract rodents like rats and mice if you bury food scraps.
I know some people who have a compost bin in each veggie patch. This way they don’t have to move their pruning, or the finished compost far!
What’s the process for composting?
Once you have located your compost bin it really is just a matter of starting to put your kitchen scraps, grass clippings, leaves etc in the bin.
I recommend that you have the bin on the ground. The worms and bacteria from the soil will travel up and start the composting process. It really is that simple.
If you want, you can buy some composting worms. This will help speed up the process.
Every time you add a layer of green material, especially kitchen scraps then you need to cover it with a layer of brown material like cardboard, paper, straw etc. Otherwise it can attract flies and rodents or start to smell.
A good compost heap honestly should not smell. If it smells then something is going wrong.
You need to keep your compost heap moist. You need to give it a sprinkling of water every couple of days.
If your compost gets too dry it will stop working! And the leaves and scraps just won’t break down.
I recommend you get a compost aerator from the big green shed or nursery. This is like a giant corkscrew or bottle opener. It really helps introduce air into your compost heap and speed up the process.
Follow these steps and in about 4 months your compost should be ready to spread on your garden!
This compost will add lots of nutrients to your plants. It will also add all those beneficial microbes into your soil. And the more beneficial bacteria in your soil, the bigger, stronger and healthier your veggies will be.
Is there anything that you can’t add to your compost?
There are a few things you shouldn’t add to your compost heap.
This includes any meat or fish products, dairy or cheese. The average home compost system can’t cope with these products and they will start to smell off!! Also, they can attract vermin like rats and mice or even snakes.
Another thing that you shouldn’t put in your compost heap is any plants or cuttings that are diseased or infested with pests.
This is because an average compost heap doesn’t generate enough heat to kill these diseases. So you will just be spreading them to other, non-diseased areas of your garden.
Also if you have sprayed your grass with weed killers then you can’t add this to your compost heap. The same goes for any pesticides. These don’t break down and will kill all your worms and microbes.
You also can’t compost bio-plastics. Even though a lot of take-away containers, including coffee cups, say they are compostable. Your average home compost heap won’t break them down. They actually need a special system to compost them.
And hopefully it goes without saying but normal plastics, glass and big planks of wood also won’t break down.
Most people wouldn’t normally add these to the compost bin, but I did find a kitchen bowl and a fork in one of my compost bins when I emptied it! Obviously, they had fallen in when I was emptying kitchen scraps and I hadn’t noticed!
Also, you shouldn’t add any dog poo or cat poo! This is because these animals primarily eat a meat diet. So you might be introducing pathogens into your garden.
This doesn’t mean that you can’t compost pet poo! You just need a separate system. I use a worm tube.
This brings me to other ways of dealing with kitchen scraps, if you don’t have enough space to have a compost bin.
What if I don’t have any garden? Can I still compost?
If you don’t have any garden space, because you live in a unit or townhouse, then try a kitchen top composting bin. All you need is a bucket with a lid, food waste and Bokashi composting mix.
You add your scraps to the bin and at the end of each day you cover it with the composting mix. This is rich in all the microorganisms that break down the food waste.
The compost made in these bins is very rich so it can’t be added directly to your potted plants. You will need to find someone who has a garden where the composted material can be buried.
I have a few people who gift me their compost! They don’t have space for it themselves, but have been encouraged to start composting after listening to me!
If you have a little more space, another option is to invest in a worm farm. This is a container system where you use compost worms to break down your food scraps.
They produce a worm tea that you can dilute and use on all your potted plants. Eventually this will also fill up, so you will need to get rid of the compost. However, it will take a fair bit longer than the bokashi bin.
Hopefully this will encourage you to try composting, if you aren’t doing it already.
And a final WHY?
You hear in the news about the need for carbon sequestering to remove carbon from the atmosphere. By composting you are doing your own little bit of carbon sequestering!