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Make a hibernaculum for frogs


While male frogs head to the depths of the pond to spend winter, females and juveniles seek out damp quarters. Create the perfect winter digs now, using an old growing bag, grass clippings and autumn leaves. The bag retains moisture to keep frogs' skins moist, while leaves and clippings insulate them from frost.

How to do it

Frog hibernaculum


Choose a sheltered spot that won't be disturbed. Dig a shallow trench the same size as the old growing bag. Lay the bag in the trench and gently firm the compost.

Cover the bag with grass clippings


Cover the bag with grass clippings or plant prunings, ensuring no unsightly edges of the bag are on view. Frogs love to squeeze into tight spaces, so pack the clippings down. 

Spread a layer of leaves


Spread a thick layer of leaves over the top. If you've chosen a windy spot, add some twigs to hold the leaves in place. Leave the hibernaculum undisturbed until April. 

Discuss this project

Talkback: Make a hibernaculum for frogs
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Vespasian 04/10/2013 at 06:47

Will toads use the same area if created?

Dovefromabove 04/10/2013 at 11:42

I'm a little concerned about the hibernaculum made using the grow bag - it could become totally waterlogged which would not be good.  If using this method I'd recommend making several good slits in the bottom of the growbag to avoid it becoming a sump.

Damp is good, totally waterlogged could be tragic.

nutcutlet 04/10/2013 at 11:48

I agree, it wouldn't take long for a growbag to be full of water, or to freeze solid afterwards

Fairygirl 04/10/2013 at 12:57

I wondered about that too. Would have thought just putting a good layer of compost on soil and then covering etc would have been well enough insulated but cool and damp. With the amount of rainfall we normally get here they'd need a raft by December!