Deadwood is not a mess — it is the engine room of the garden

Pick up a rotting branch in any British wood and you will find more life on it than in most garden ponds. Deadwood is not the end of a tree; it is the slow, generous middle act of one. Around a third of Britain's woodland species depend on dead or dying wood at some stage of their lives, and many will happily use a modest garden if we let them. A stump beneath the hedge, a stack of logs behind the shed, a heap of prunings beside the compost bin: these are not untidiness, they are habitat. A garden with nowhere for rot to happen is quietly losing its insects — and with them its birds, its bats, its hedgehogs and its fungi.

What a good log pile actually supports

Rotting wood is a food chain in three dimensions. Saproxylic beetles — those that depend on deadwood — include the stag beetle in the south-east and the lesser stag beetle more widely, whose larvae spend three to six years grubbing through damp, decaying timber before emerging as adults in early summer. Solitary bees and wasps nest in beetle-bored tunnels; hoverfly larvae graze the slime that gathers in rot hollows; woodlice, centipedes and millipedes move in behind them.

• Fungi are the true recyclers. Birch polypore, King Alfred's cakes on old ash, candle-snuff on ash stumps and chicken of the woods on oak all fruit on decayed timber, unlocking nutrients and returning them to the soil.
• Birds pick over the carcass: great spotted woodpeckers and nuthatches hunting grubs, treecreepers working vertical surfaces, wrens and robins searching the crevices.
• Bats hawk the night shift that rises from sun-warmed logs, and hedgehogs will hibernate happily under a heap of brash and leaves.

Four kinds of deadwood worth keeping

Variety matters more than volume, so aim for a mix of sizes, tree species and orientations.

• Standing stumps — cut at knee or waist height. They decay slowly and suit beetles that need upright, sunlit deadwood. Leave the bark on and let ferns and ivy colonise.
• A ground-level log pile — three or four logs of 20–30cm diameter, part-buried in soil or leaf mould, is worth more than a dozen thin sticks. Contact with damp earth is what lets the fungi in.
• A brash heap — the twiggy, awkward prunings. Piled loosely in a corner, they give nesting cover and hibernation sites.
• A dead hedge — driven hazel or willow stakes with prunings woven between them. Boundary, shelter and food bank in one.

If you have room, lay one log so that half sits in shade and half catches the sun; a warm, sheltered surface will be busy with insects within a fortnight of the first mild spell.

Doing it safely and sensibly

• Check anything overhead. Standing dead trees, and dead limbs above paths, play areas, greenhouses or parking spaces, should be assessed by a qualified tree surgeon. Remove what could fall on someone, then keep the timber on the ground.
• Keep piles away from buildings. Not tight against house walls, sheds or fences, where damp can creep in.
• Never use treated timber. Fencing, decking, pallets and old railway sleepers contain preservatives and have no place in a wildlife habitat.
• Do not import wood. Moving logs between gardens or from abroad risks spreading tree diseases, including ash dieback. Use timber from your own plot or a very local tree.

Making it look deliberate

Deadwood need not look scruffy. A stumpery is one of the oldest garden devices in Britain: upturned root plates and mossy stumps arranged in dappled shade, planted with hart's tongue fern, wood anemone, wild garlic and primroses. The roots give crevices for ferns and the rot beneath feeds the soil above. Logs can edge a border or line a woodland path, and a short section of trunk set upright and topped with a planter reads as a feature rather than a lapse in maintenance. Group piles in threes rather than scattering them singly, and they will look like a decision you made on purpose — which they are.

Seasonal notes through the year

Winter. The best months for fungi: bracket fungi harden on stumps, jelly ear swells with rain, and woodpeckers begin drumming on standing dead timber in late winter.

Spring. Solitary bees and wasps emerge and hunt for ready-made tunnels in beetle-bored logs; queen bumblebees investigate old stumps and tussocky brash before founding a nest.

Summer. From late May to July, on warm evenings at dusk, look for stag beetles in flight around south-facing log piles in southern England. By day, hoverflies and ichneumon wasps work the surface.

Autumn. The great fungal flush — chicken of the woods, shaggy inkcap, sulphur tuft — and hedgehogs seeking a brash pile deep enough to sleep in. This is the moment to resist the tidy-up: leave the pile alone, add this year's prunings on top, and let the ecosystem carry on quietly underneath.