Have you ever wondered how, or even why, to compost in a tumbler? This guide offers step by step instructions to make compost FASTER than in a conventional compost bin.
For successful composting in a tumbler you will need to know where to put the tumbler, what to put into it, how often to turn it and to know when it is ready.
Why use a compost tumbler?
When you turn a compost tumbler regularly you bring more air into the compost. This feeds the organisms breaking down the materials, supercharging the composting process.
Compost tumblers process moderate amounts of material really well, they can be used for kitchen and garden waste.
Position your tumbler on hard standings, useful on a patio or if you don’t have an area of ground to site your compost bin.
Tumblers are not great if you have a large garden or a lot of material to compost. In this case the chambers for composting are relatively small.
Like me, you could use both a traditional bin system and a tumbler.
How to compost in a tumbler
Step 1: Where to put the tumbler?
The purpose of composting in a tumbler is to make compost quicker than if you were using a conventional bin. Composting is a process that both requires and produces heat.
Put your tumbler in full sun to help speed the composting organisms along.
It will still work in partial or deep shade, it just will take longer to make compost.
Put your tumbler somewhere that you pass by regularly, like outside your back door or on the way to your bike/car. Why? Because then you will see it and turn it.
Step 2: What to put in the tumbler?
Kitchen scraps (‘greens’) that would go in any other type of compost bin. Fruit and veggie peelings, coffee grounds, egg shells.
Cutting up the materials for composting into smaller pieces (like cutting up a banana skin rather than putting it in whole) WILL make composting happen faster. It’s physics, the surface area available for the microbes to work on will be greater if you cut the veggie bits into smaller pieces.
Garden waste (‘greens’) fresh leaves, grass clippings, annual weeds
Garden waste (‘browns’) autumn leaves, small twigs, wood chips. If you put things in that are too branchy they will not break down in a short space of time.
If you do put tougher branchier materials in, you can always take them out and throw them into your next batch. They will EVENTUALLY break down, just might take a bit longer.
Shredded cardboard and paper (‘browns’) again keeping it smaller will help to make composting go a bit quicker. These ‘browns’ are carbon rich materials that are important for keeping the balance within the tumbler.
The ratio of greens to browns in a conventional bin I usually use is around 1 part browns to 1 part greens. Same for the tumbler. But keep an eye on it and tweak it if you need to.
A spadeful of old compost is the magic that will kick start the whole process. Old compost is full of bacteria, protozoa, fungi and all the other life that is important for the composting process.
Putting it into your mix gives a boost, these organisms are already working, reproducing and with a good mix of food supply from your composting materials they can just keep doing what they are already doing.
Filling your tumbler can either be done in one go, if you have a lot of materials available. Or it can be done bit by bit over time as you create kitchen scraps and garden waste. The longer it takes to fill, the longer it will take to make compost.
Step 3: Turning the tumbler
Tumbler should be turned every 2 or 3 days. This keeps air flowing through, keeps the food for the bacteria moving around the bin so that they can be fed well. It only needs to be a quick spin.
If you are adding as you go, this will be easy when you come to add the kitchen scraps or garden waste, give it a turn.
Step 4: How do I know when the compost is ready to empty from the tumbler?
The time it takes for the compost to be ready will vary, it depends on the time of year (if it’s summer and hot it will happen quicker). And on the size of what has gone into the tumbler. And on how often the tumbler has been turned.
In ideal conditions it will take about 1 month, or up to 6 months in less ideal conditions.
You’ll know when it is ready – it should smell earthy, it should be a dark brown colour, there should no longer be visible bits of kitchen scraps in it.
This is the time to empty it. Simply tip the tumbler up so that the hatch is facing down. Place a bucket underneath the hatch, and open it. The compost will fall out into the bucket ready to use in your garden.
Pro tip: If you are not going to use your compost straight away it’s a good idea to keep it moist and stop it from drying out. Store it in a cool, dark place if possible.
How long does it take to compost in a tumbler?
Anything from a month up to 6 months. There are lots of things that affect how long it takes.
- Size of materials, cut up cabbage leaves will be quicker than whole leaves
- Position: full sun will be quicker than shade
- Time of year: summer will be quicker than winter
- How much turning: every couple of days is optimal
Do I need to put dirt in my tumbler?
Yes it is a good idea to add in a spadeful of soil or old compost that is rich in soil life to kick start the process. This is full of all the organisms that are needed to make the decomposition happen, that’s why we do it.
Should I turn it every day?
Every few days should be enough. Daily and you can start to slow down the composting process. It needs time to heat up.
Should I add worms to my tumbler?
No. The compost inside tumblers gets hot. This is not the right conditions for worms, they will die. Add worms to your compost bin, not your tumbler.
When do I stop adding to my tumbler?
When the tumbler is full – which is not so full that the contents doesn’t move when you turn it. Usually the chamber should be around three quarters full.
Should compost tumblers be in sun or shade?
In the UK sun is best as the heat will help with the composting process. In partial or deep shade, composting will still happen. It will just be slower.
Should I add water to my compost tumbler?
If the compost is looking too dry then yes you could add a bit of water. Add a little and then observe, you can always add a little more.
Compost tumbler green to brown ratio
I use 50:50 or 1 part green to 1 part brown. This is done pretty roughly and by eye. But if I have some green materials to add then I will try and also add some brown and vice versa.
What not to put in a compost tumbler?
Meat, fish, dairy, cat and dog poo.
I would only compost these in a system which is guaranteed to get hot and stay hot. Most back garden systems are not temperature controlled in the way that industrial systems are.
Rats and other pests will be attracted to the bin. The materials will not break down adequately.
So there we have it, all that you need to know about composting in a tumbler. What is your experience of using a compost tumbler? Have you tried to use one, or made your own? I would love to hear your experience in the chat below.