The woodlouse is not a garden helper in the “classic” sense: it doesn’t hunt pests, nor does it help in pollination.However, as a detrivore, it is one of the keys to successful gardening. Indeed, it helps feed the soil and plants by breaking down all plant waste (rotting wood, dead leaves, etc.).
Discover this unexpected ally of the gardener.
Contrary to what one might think, the woodlouse is not an insect. Indeed, it belongs to the class of Crustaceans and the order of isopods. In short, it’s a relative of crabs and lobsters!
A woodlouse is easy to recognize:
The species that you often find in the garden include:
The woodlouse is a land crustacean. Its ancestors came from the sea, and till today these animals still breathe through gills and have a a non-waterproof shell. These features make it vulnerable to drying out, so it can only survive in a humid, moist atmosphere. That’s why it comes out mainly at night and on rainy days.
As a recycler and detrivore, the woodlouse feeds on dead organic matter: rotting bark, dead leaves, or even corpses of insects or animals. It can supplement this diet with mushrooms, roots, or young shoots. However, this vegetarian part of its diet is not enough to cause damage to crops.
Did you know?
Like lichen on trees indicating a non-polluted atmosphere, and voles, the woodlouse is an excellent indicator of healthy soil. Indeed, it is particularly sensitive to heavy metals (lead, zinc, copper, etc.) and disappears if these are present in excess.
In the garden, you will find the woodlouse wherever it is humid enough for it:
You may encounter a woodlouse in your house (basement, kitchen, garage, etc.). If there’s only one, it is not a problem. However, if there are more, it could mean there is a water leak or infiltration somewhere. You would then need to investigate.
Several species turn up regularly around the house and vegetable plot, and they are told apart mainly by size, colour and behaviour. Here is how the ones named in this article compare.
| Common name | Scientific name | Size | How to tell it apart |
|---|---|---|---|
| Common rough woodlouse | Porcellio scaber | Up to 0.7 inches (1.7 cm) | Steel grey; the species most often found indoors |
| Wall woodlouse | Oniscus murarius | Not given | Lighter grey, almost white |
| Moss woodlouse | Philoscia muscorum | Up to 0.4 inches (1 cm) | Grey-brown colouring |
| Common pill bug | Armadillidium vulgare | About 0.8 inches (2 cm) | Grey, and rolls into a ball when threatened |
Whichever species you find, all of them work as recyclers of dead organic matter.
Just like the earthworm, the woodlouse is vital for the health of your soil in the vegetable garden and yard. By decomposing dead organic matter, it makes nutrients available again for plants. It thus contributes to the soil’s proper ecological balance. Therefore, it’s important to protect it.
For this, nothing could be simpler. Just provide the woodlouse with shelter, especially near areas where it will be most useful. For instance, you can:
Finally, even though it might seem absurd, resist the urge to always remove moss from the lawn. It indeed forms an ideal biotope for the woodlouse. If possible, maintain a part of the garden with some patches of moss, it will make woodlice happy.
To summarize, far from being a pest, the woodlouse plays a crucial role for the health of your soil by recycling dead organic matter. All you have to do now is to set up a few well-placed shelters to make its life easier in your garden.
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