Chris Collins on…making a hibernaculum

Everyone needs somewhere safe to retreat to – and our wildlife needs it more than ever. The bear needs a cave to overwinter, the spider needs a web for safety and food, and reptiles need an underground bunker for warmth.
In your garden it’s crucial to provide a place for important predators to shelter, such as insects, lizards, toads, bats and, if you have a larger garden, possibly even snakes. Now I know snakes might not be everybody’s favourite creature, but I love them, and gardening is all about creating balance. While working in Western Africa, I soon learnt their value, keeping rat populations in check!
A hibernaculum is a lovely way to provide many of these creatures with a comfy habitat – while also encouraging them to stay in your garden and naturally mop up pests.
Hibernaculums consist of an underground chamber, with good access points, and are filled with natural materials like logs and rocks. You don't need to compromise the aesthetics of your garden either - with clever planting around your hibernaculum you may not even notice it’s there.
Step-by-step hibernaculum
To build a hibernaculum, simply follow these five steps:
- Choose a sunny location and dig a deep hole (around 50cm deep and 1 metre across).
- Pack the space with small logs, rocks, and branches with a few gaps in between.
- Insert a cut-off drainpipe base of your structure and this will act as an entrance tunnel.
- Cover your habitat with soil (around 50cm high) and sow grass or wildflower seed on the top to encourage more wildlife.