The short answer is yes, you can certainly put compostable plastic bags in the compost and they will break down, but you have to be sure it’s the right kind of plastic.
Why compost in the first place?
Starting a compost pile is a great way to go green. It helps reduce waste and shrink your environmental footprint.
Landfills are not only a problem because of their size, but because they let off huge amounts of methane and other greenhouse gases as the products in them decompose.
Keeping garbage out of them is a huge priority for environmentalists.
This means that composting at home or through curbside pickup is one of the best things you can do for the environment and our atmosphere.
However, it comes with a downside, which is that it can get pretty messy. Your old kitchen scraps are soggy, smelly and worst of all, can attract pests to your home.
To keep their home compost pile neat and tidy, many people keep theirs in a plastic bag.
With modern compostable bags, you don’t have to empty them out because you can toss them straight in the compost pile when you’re ready.
Table of Contents
What type of bags should I use?
There are many bags and other plastic materials on the market that are marketed as being biodegradable and environmentally friendly.
While it is true that they will break down eventually if they are thrown in a landfill, they are not suitable for compost.
To be truly compostable, the bags must say that explicitly on their label. Bags that are only biodegradable take longer to decompose and often leave a toxic residue behind.
Compostable bags will break down into water, carbon and biomass and do so within the same timeframe as plant fibre (cellulose).
This means that when a compostable bag breaks down it’s molecules will stay in the soil and help support the growth of other plants.
How long will it take for my compostable bag to break down completely?
This depends on a lot of factors. Usually compostable plastic breaks down at a slightly slower rate than food and garden scraps.
Some compost is more active than others, meaning it contains more bacteria that help eat away at and break down the materials you put in it.
When composting at home, it’s important to add soil to the pile, which is a great source of these microbes and will help speed along the process.
It also prevents your compost from turning into nothing but a pile of rotting food.
Water and air are also key ingredients. All life forms on planet earth require these two elements, and the bacteria in the heart of your compost pile are no different.
Watering and aerating your compost pile by turning it over is a great way to speed along the process.
The final element your compost requires to decompose is warmth.
The bacteria inside the pile will generate their own body heat, but it helps to keep your compost in the sun if possible.
Commercial compost is done at high heat so that it breaks down much faster than home compost, which can take a year or two to turn into something usable and helpful for your plants.
One last tip: the greatest friend a compost pile can have are the wriggly little creatures that populate the earth.
Worms are incredible at eating and digesting any organic material in the soil, so you should make sure to add them into your compost pile to speed up the process. But you probably already knew that.
Will compostable bags break down in a landfill?
Chances are they probably won’t. A landfill is only a pile of garbage and doesn’t contain the organic elements that plant materials need to break down. There is no bacterial life that will eat away at the fibres and there certainly isn’t any air at the bottom of a landfill.
This means that landfills are the worst place to throw something if you want it to break down and be returned to nature.
One option, if you don’t have room for a compost pile, is to bury your compost scraps in the soil.
Because they will be surrounded by soil, they will be covered by the good, hardworking microbes that will turn them into compost for your garden.
All you have to do is bury some food scraps in your garden and your plants will thank you!
No, neither compostable nor biodegradable bags can be recycled. In fact, putting them in with the recycling can cause problems at the sorting plants.
Not only will they have to waste time in pulling out the bad bags from the rest of the load, but they make a mistake and leave the compostable bags in with the rest.
This can contaminate the rest of the batch.
We know you want to do your part for the environment – but putting composting bags in the recycling is self-defeating for both of these wonderful eco-friendly practices we should all be doing.
Check the ingredients label
When buying compostable or biodegradable plastic, it’s important to read the fine print.
Many of these materials contain harmful substances like BPA and heavy metals like cadmium, lead. or mercury in some cases
If you put these bags in your compost pile, traces of these elements will be left behind in your soil.
Be wary of these products. Many producers take advantage of your desire to help the planet, but their products are not safe or non-toxic.
Even if something is advertised as being natural, green or eco-friendly, you need to double check it doesn’t have some of these nasty chemicals.
Composting is a practice that is becoming more and more widespread, which is great news for mother nature.
You don’t need compost bags to do this, but they do ensure the whole procedure is clean and tidy, and some municipalities actually require them for compost pickup.
It’s important to do your research and buy the correct type of bag. If it’s not the right one, it may not decompose nicely and it won’t be as helpful for your garden as you like.