Why a Log Pile Belongs in Every Wildlife Garden

Dead wood is one of the most valuable habitats you can offer, and it is also one of the scarcest. tidy gardens, tidy parks and tidy woodland management have swept away much of the rotting timber that invertebrates evolved to depend on. A simple stack of untreated logs in a quiet corner puts some of that back, and it costs you almost nothing.

As logs decay, they are colonised by fungi, and those fungi soften the timber enough for beetles, woodlice, millipedes and the larvae of many flies to move in. Those creatures are food. A wren working a log pile in January, flicking through the gaps for a dormant spider or a hibernating grub, is doing exactly what wrens have always done. You are not feeding the birds so much as rebuilding the larder they lost.

Choosing the Right Spot

Shade and damp are your friends here. A pile in full sun will dry out, crack and support far less life, so look for the north or east side of a shed, fence or hedge, or the ground beneath a mature shrub. Somewhere the soil stays cool and slightly moist is ideal.

A few practical points before you start:

• Pick a spot you are happy to leave undisturbed for years, ideally out of sight of the tidy-up instinct.
• Avoid ground that floods in winter, but don't worry about a bit of dampness.
• Keep it away from the house if you are concerned about damp against a wall, and away from where children play roughly.
• Log piles can attract adders in some areas and wasps may nest in sunny ones, so place yours thoughtfully if either is a concern.

If space is tight, a pile one metre long and half a metre high still does a great job. Even a modest stack against a shady boundary will pull its weight.

Building the Pile

The timber matters more than the technique. Use untreated wood only — no varnish, no preservative, no old fence panels or railway sleepers. Hardwoods such as oak, ash, beech, birch and fruitwood are excellent; conifer logs are fine too and rot a little faster, which is no bad thing.

A mixed pile out-performs a uniform one, so vary the log diameters from thumb-thick to forearm-thick. Lay them loosely, in alternating directions every so often, so that gaps and tunnels remain between the logs rather than everything settling into a solid block. Those gaps are the whole point — they are where invertebrates shelter and where birds poke their beaks.

• Put the largest logs on the bottom, in direct contact with the soil, so damp and fungal threads can wick upward.
• Leave the bark on. It harbours eggs, pupae and tiny hibernating adults.
• Drill a few holes, 8–10mm wide and a few centimetres deep, into the cut ends of a couple of logs to give solitary bees and beetles a head start.
• Tuck fallen leaves, a little leaf mould or some moss into the crevices.
• Don't nail or wire it together. Stability comes from stacking sensibly, and movement is harmless.

If you want to be generous, sink a few upright stumps alongside the horizontal stack. Standing dead wood rots differently from lying wood and attracts a slightly different cast of characters.

What Will Move In

Patience is required for the first season, then things accelerate. Expect woodlice and centipedes within weeks, beetle larvae by the following spring, and fungi — the bracket and jelly sorts, plus the thread-like mycelium running through the wood — almost immediately. Stag beetle larvae, where you are lucky enough to live in their southern strongholds, take several years to develop in buried or partly buried rotting wood.

Larger creatures follow. Slow worms and frogs use the pile for shelter and for the warmth it holds on cool mornings. Hedgehogs may nest in a substantial stack. Solitary bees and overwintering butterflies tuck into the drier upper layers. A well-made pile is less a single habitat than a small apartment block.

The Birds That Will Come

Wrens are the star turn. They are naturally crevice feeders and will work a log pile methodically, hopping through the tunnels and vanishing between the logs before popping out the other side. Robins take a more watchful approach, perching on the top log and dropping down onto anything that moves.

Watch also for:

• Dunnocks, which scratch around the base in the leaf litter.
• Blackbirds and song thrushes, turning over leaves at the edges and hammering at snails against a sturdy log.
• Great tits and blue tits, gleaning from the bark and from the undersides of the topmost logs.
• Nuthatches and treecreepers in larger gardens with mature trees nearby.
• Great spotted woodpeckers, which will excavate decaying wood in search of beetle grubs, especially in a taller standing stump.

Leave the pile alone through winter and you will find birds visiting on the hardest frosts, when other food is locked away.

Looking After It, Mostly by Not Looking After It

The single best thing you can do for a log pile is to leave it be. Resist topping it up with grass cuttings or garden waste, which smothers the wood and turns the pile anaerobic and useless. Don't move it, don't tidy the leaves off it, and don't worry if it settles and shrinks.

If you want to keep the supply going, start a second pile quietly nearby and let the first one rot down entirely. Rotting wood eventually becomes wonderful crumbly humus, and that humus is superb for the soil and for the plants around it. When the logs have all but disappeared, simply add fresh ones on top and let the cycle continue.

Add a shallow dish of water nearby, or a small wildlife pond if you have room, and you will have created a corner that supports invertebrates, amphibians and birds at every stage of their lives — from a single sheltered beetle to a wren hunting through the frost.