Why a log pile earns its corner

A log pile is the cheapest piece of wildlife habitat you will ever build, and often the busiest. A single decaying branch can feed beetle larvae for years, shelter a toad through February and give a solitary bee somewhere to sit out the frost. Unlike a pond or a wildflower strip, it costs nothing but a little forethought and the pruned branches you were about to shred anyway.

The catch is that a heap of cuttings dumped in a corner rarely does the job. A proper pile is stacked with intent: dense enough to hold damp, loose enough to leave gaps, and placed where it will stay cool and undisturbed. Build it well and it will quietly fill with life within a fortnight.

Choosing the right spot

Shade and damp are the whole point. A north or east-facing corner is ideal, particularly under a mature hedge, behind a shed or beneath the canopy of a fruit tree. Full sun will dry the pile out and make it far less useful.

• Keep it at least a metre away from the house, shed walls and fence lines you share with neighbours.
• Leave clear ground around it so you can still mow or walk past without disturbing it.
• Avoid anywhere that floods in winter, but aim for soil that stays cool and slightly moist.
• Put it somewhere visible from a window. You will notice far more of what moves in.

If you have room, two small piles are better than one enormous one. You can leave one completely alone while the other is topped up, and nothing hibernating gets disturbed.

What to stack, and what to leave out

Almost any native hardwood works well. Apple, oak, ash, hawthorn, field maple, birch and willow are all excellent, and mixed sizes are better than uniform ones. Aim for a range from pencil-thin twigs up to branches around 20cm across. Leave the bark on: it is a habitat in its own right.

Dead wood that is already soft and crumbly is gold dust, so resist the urge to tidy it away. Add a few fallen leaves, a handful of moss and a couple of flat stones for good measure.

What to leave out is just as important:

• Timber treated with preservative, painted wood, MDF or old pallets that have been chemically treated.
• Grass clippings, compost, kitchen scraps or anything that will turn sour and attract rats.
• Freshly shredded material, which mats down into an airless, smelly layer.

Building it, layer by layer

Start with the chunkiest logs along the bottom and set them partly into the soil. Contact with bare earth keeps the pile damp and lets beetles and centipedes walk straight in from below. Stack loosely in a criss-cross pattern rather than laying everything parallel, so air pockets remain between the layers.

Before you go any further, sink two or three upright stumps into the ground, roughly 30 to 40cm deep with 20cm left showing. These mimic the rotting stumps that stag beetle larvae need, and they take years to develop, so the sooner they go in the better.

Build upwards with progressively thinner branches, tucking smaller twigs into the gaps. Finish with a light cap of leaves and moss to hold humidity. For solitary bees, either drill holes of 6 to 10mm into the south-facing side of a log, or bundle 15 to 20cm lengths of hollow stem — bamboo, old buddleia or teasel — and wedge them into the top. A finished pile about a metre wide and half a metre high is plenty.

Who moves in, and roughly when

The first arrivals are woodlice, millipedes and slugs, usually within days. Fungi and moss follow, staining the wood and softening it. By autumn you can expect violet ground beetles, devil's coach horse beetles and the odd centipede hunting through the lower layers.

Frogs, toads and newts move in as the weather turns, burrowing into the damp leaf litter at the base. Slow worms will bask on a sunny edge if the pile sits near a warm border. Hedgehogs may use a large, tucked-away pile for hibernation, though they are fussy and will only commit if it feels secure. Come spring, bees and other insects emerge from the bored holes and hollow stems, and birds will start turning over the top layer looking for grubs.

Leaving it alone

The hardest part is doing nothing. Resist tidying, and never burn a pile that has stood for more than a season — it is almost certainly occupied.

If you must move it, wait until late spring, ideally April or May, when everything has woken and dispersed. Lift material with a fork rather than a spade, work slowly, and set anything you find to one side in a bucket of leaves. Keep an eye out for great crested newts, which are protected, and stop and seek advice if you spot one.

Top the pile up each year with fresh prunings, adding them to the top and letting the bottom rot down quietly. Replenish the hollow stems and check the bee holes are clear. Beyond that, your only real job is to walk past, glance at it now and then, and enjoy the fact that the scruffiest corner of the garden is doing the most work.