Willy the worm soft toy
The mascot for kids and adults in a 73 cm long format!
15,28 €
Practical guide
Vermicomposting
Guide contents
01Getting started5▸
02Choosing your model5▸
03Daily care4▸
04Solving a problem4▸
05Living with your wormery6▸
Other topics in the guide
Should you stir your wormery? The role of aeration
Good news for beginners: unlike a garden compost heap, which needs turning regularly with a fork, a wormery doesn't need to be stirred as a matter of routine. That doesn't mean aeration is unimportant — quite the opposite. Here's what you need to know to do the right things, without overdoing it.
Aeration is essential for decomposition
The breakdown of your waste begins even before the worms come into play: it is first bacteria and fungi, naturally present on organic matter, that start the decomposition process. These micro-organisms need oxygen to work efficiently — this is known as aerobic decomposition. Good air circulation in your wormery is therefore a basic requirement for quality compost, even before we talk about the worms themselves.
The worms help with aeration, without you having to step in
This is where a wormery really differs from a traditional compost heap. Your worms don't stay still: they move constantly through the material in search of fresh food, climb from one tray to the next through the holes that connect them, and dig small tunnels near the surface. This constant movement mixes and aerates the material by itself, rather like burrowing worms do in natural soil.
On top of this comes the design of your wormery itself: each tray leaves a slight gap where it fits onto the one below, and it is through this gap that air flows naturally from one level to the next — all designed so that you don't have to step in. In the vast majority of cases, these mechanisms are more than enough to maintain good aeration, without any need for manual stirring.
Key pointsBy moving naturally from one tray to another in search of fresh food, your worms mix and aerate the material themselves — that's the whole principle of the tray wormery.
When a little helping hand is useful
There are nevertheless situations where light stirring helps. The most useful everyday habit is simply to work your new scraps gently into the top layer rather than leaving them as they are on top: this speeds up how quickly the worms get to them and makes the wormery less attractive to fruit flies, which are drawn to fresh scraps left on the surface.
If you are still worried about a lack of air — after a period of heavy feeding, for example — you can safely give the contents of the active tray a gentle stir. Use a tool that won't harm your worms: a wooden spoon, a small hand trowel, or our Mini Mixing Rake, designed for exactly this job. You can also do it with your bare hands, or with rubber gloves if you'd rather not touch the compost directly. Light, occasional stirring of this kind won't disturb your worms in the slightest.
Signs of a genuine lack of aeration
Too much moisture or too many fresh scraps can cause the material to compact and block the flow of air. Decomposition then becomes anaerobic — that is, it takes place without oxygen — which encourages unpleasant smells. A few signs should alert you: a smell that lingers even though the wormery is otherwise well looked after, material that stays compact and soggy to the touch, or scraps that no longer seem to be breaking down normally.
Well aerated: light and crumbly
Compacted and soggy: a warning signIn this case, a more thorough stir of the active tray helps to let air back in. Also remember to cut back on feeding for a while until things rebalance — we cover this in detail in our guide What do worms eat? — and to increase the proportion of carbon-rich materials (cardboard, paper, straw…), which give the material structure and prevent exactly this kind of compaction.
Don't overdo it either
On the other hand, there's no need to turn your wormery deeply on a regular or routine basis: this is useful as an occasional fix, but it disturbs your worms more than simple surface stirring and risks damaging the cocoons laid in the material. Moderation is key: a light, occasional stir rather than deep turning at fixed intervals.
In fact, if you already follow the weekly routine described in our guide What do worms eat? — gently stirring the active tray when you add your acidity regulator — you are already, without realising it, providing the aeration your wormery needs in the vast majority of cases.
In summary
No, a wormery isn't stirred like a garden compost heap. Its ventilation holes and the natural movement of your worms do most of the work. A light, occasional stir — when adding scraps, or if you notice an unusual smell or compaction — is enough to take care of the rest. If bad smells persist despite these steps, head to our guide on wormery problems and smells to identify the exact cause.
