Why a log pile is one of the best things you can add to a garden

Dead wood is one of the scarcest habitats in Britain. In a working woodland, fallen branches are left where they land, rot slowly over decades, and support an entire community of invertebrates, fungi, mosses and lichens. In most gardens, anything that falls is tidied away by the end of the weekend. A log pile puts a little of that woodland back.

It is cheap, it takes an afternoon, and it needs almost no maintenance. In return you get a slow-burning habitat that beetles, solitary bees, amphibians, hedgehogs and fungi will find within a season or two. Unlike a pond, there is no liner to buy and no risk of a toddler falling in. It simply sits at the back of a border doing quiet, useful work.

Choosing the right spot

Position matters more than most people expect, so think about what you want to attract.

• A sunny south or west-facing edge warms quickly in the morning and suits basking invertebrates, solitary bees and slow worms.
• Dappled shade beside a hedge or mature shrub stays damper and is better for wood-rotting fungi, beetles and amphibians.
• Keep it at least a metre from house walls, sheds and timber fences, so damp does not creep into structures.
• Avoid the middle of a lawn or a main path. The pile will be with you for years, and you do not want to be mowing around it or stepping over it.
• Leave the leaf litter that gathers around it. That soft, crumbly layer is where a great deal of the activity happens.

If you can manage two piles — one in sun, one in shade — you will support a much wider range of species.

Which wood to use, and which to avoid

Native broadleaves are ideal: oak, beech, ash, birch, apple, cherry, sycamore, willow and field maple all rot well and attract different fungi. Oak and beech are the slowest to break down and last longest. Willow and birch rot quickly, which suits beetles that need softer, wetter timber. Mixing species and diameters is the single best thing you can do.

Leave the bark on wherever possible, and vary the log sizes from wrist-thick to arm-thick. A few short lengths of hollow stem, a couple of old stone bricks and a small heap of twiggy prunings will add gaps that a tidy stack of round logs never has.

Things to leave out of the pile:

• Treated, painted, stained or varnished timber, including old fence panels, decking offcuts and most pallets.
• Old railway sleepers, which may still hold creosote.
• Yew, laburnum, laurel, rhododendron and walnut, whose wood and sap can be harmful to pets and children.
• Ash from an area with ash dieback — leave it where it falls rather than moving it about the countryside.

Conifer logs are fine to include in small numbers, though they tend to rot faster and support fewer species than oak or beech.

How to build it

Start by loosening the soil slightly where the pile will sit; bare earth beneath a log pile is much more useful than a paved base. Lay a bottom course of larger logs, half-sunk if you can manage it, then stack upwards in loose layers rather than tight rows.

Push a few logs into the ground upright so they stand like short posts — beetles and solitary bees use the exposed end grain. Aim for a pile at least a metre square and 60 to 90 centimetres high, or three smaller piles spread around the garden. Keep a couple of gaps running through the middle of the stack; these act as corridors and stop the centre going sour and airless.

Finish by scattering leaf mould or a thin layer of soil over the top. That encourages fungi to colonise, and you may soon see ferns, foxgloves or wood anemone seedlings appearing. If you have a stump you can spare, cut it at 30 to 60 centimetres and leave it standing nearby. It will be riddled with exit holes within a few years.

Keeping it safe and undisturbed

The main safety risk is not wildlife — it is you. A pile of dry logs looks exactly like a stack of bonfire material, and hedgehogs, toads and slow worms will happily hibernate inside it. If you ever intend to burn garden waste, build that heap somewhere else, move it to the burning spot on the day, and check it thoroughly before lighting.

Otherwise, keep the pile clear of paths and play areas, avoid stacking it so loosely that it topples, and never treat it with preservative. Do not shift it between October and March, when residents are hibernating. If you must move it, do so gently and by hand, and rebury any creatures you uncover. Dogs may nose at it, which is usually harmless, but the woods listed above are best kept out of reach of pets.

What to watch through the year

In spring, look for small round holes in vertical logs where solitary bees have emerged, and for the powdery frass of beetle larvae working under bark. Summer brings lesser stag beetles, longhorn beetles and the first bracket fungi swelling on the shaded side. Autumn is the great fungal season — jelly ear, candlesnuff and sulphur polypore all appear on damp wood, and hedgehogs will be prospecting for a hibernation site. In winter, leave the pile alone and enjoy it from a distance: frost outlining the fungus caps, a fresh hole in a log, a bird poking about in the leaf litter at its base. The quiet months are when most of the work is being done.