Why the spot you choose matters more than the box

A nest box is only ever as good as the place you hang it. You can spend a small fortune on a beautifully made oak box with a hinged lid and a slate roof, but if it faces the wrong way or sits at chest height beside the shed door, it will sit empty year after year. Get the siting right, on the other hand, and a plain untreated timber box screwed to a north-facing wall can raise brood after brood of blue tits for a decade.

Thankfully, the rules are simple and they've been refined by decades of garden bird monitoring. Face the box somewhere between north and east, mount it two to five metres up, and keep it out of the prevailing wind and the glare of the midday sun. That's the core of it. Everything else is fine-tuning.

Face it between north and east

This is the single most useful piece of advice in this article. A nest box facing north through east avoids the strongest sun of the day, which in a UK garden arrives from the south and west through late morning and afternoon. A box that bakes in direct sun can overheat dangerously in June, and overheating is one of the quiet killers of nestlings.

A north-to-east aspect also shelters the entrance hole from our prevailing south-westerly winds and the driving rain that comes with them. A wet box is a cold box, and a cold box is bad news for small chicks with no feathers to speak of.

If your garden offers no suitable north or east facing surface, don't panic. A spot in deep shade, tucked under the canopy of a mature tree or against a wall smothered in ivy, is a reasonable compromise. Just avoid an exposed south or west facing wall in full sun.

Height: aim for two to five metres

Two metres is the practical minimum. Below that you're inviting cats, and you're also putting the box at eye level where the comings and goings of a household disturb the birds.

• Two metres: the floor, really. Only use it where there's no cat traffic and the box sits above dense, prickly shrubs.
• Three to four metres: the sweet spot for most garden birds — blue tits, great tits, coal tits, nuthatches and house sparrows.
• Four to five metres: good for starlings and tree sparrows, and it puts the box well beyond the reach of a casual squirrel.

Whatever height you choose, make sure you can still get a ladder to it safely. You'll want to clean the box out each autumn, and a box you can't reach is a box that slowly fills with old nesting material, parasites and damp.

Sun, wind, rain and unwelcome visitors

Once the compass direction is sorted, check the site itself. There should be a clear flight path to the entrance, with no twig or branch within a metre or so where a magpie or grey squirrel could sit and reach in. Some cover nearby is welcome, though — birds like to approach a box under the shelter of foliage rather than across open lawn.

Tilt the box very slightly forward, just a few degrees, so rain runs off the roof and away from the entrance rather than trickling inside. Fix it firmly; a box that rocks in the wind will be abandoned.

If squirrels or great spotted woodpeckers are regular visitors, fit a metal plate around the entrance hole. A baffle on the mounting pole or tree helps too. Never use a box with a perch below the hole — perches exist to help predators, not birds.

Nest boxes near ponds and wetland edges

If your garden has a pond, a boggy corner or a ditch that runs wet for most of the year, you're sitting on a goldmine. Water means insects, and insects mean well-fed chicks. A box within fifty metres or so of a pond will often fledge stronger broods than one in a dry, tidy corner of the same garden.

A few wetland-specific pointers:

• Keep the box at least two metres back from the water's edge. Posts rot fast in damp ground, and rats travelling along watercourses appreciate easy access.
• Open-fronted boxes for wagtails and spotted flycatchers work well on a sheltered wall or sturdy post facing north to east, with some cover nearby.
• Don't site a box where a heron, crow or magpie can perch directly at the entrance.
• Leave a winter roosting box up too — wrens and tits will use them on cold nights, and damp gardens are cold gardens.

Put it up, then leave it alone

The best time to hang a box is autumn or winter, between September and February. Birds will use it as a winter roost, and they'll have time to inspect it as potential nesting territory in early spring.

After that, the hardest thing is doing nothing. Resist the urge to open the lid and check on progress. Nesting season runs roughly from March to August, and disturbance at the wrong moment can cause a parent bird to desert. Clean the box out once the season is over, using hot water and a stiff brush — never chemicals — and let it dry thoroughly before putting it back.

If nobody moves in during the first year, be patient. A new box can take two or three seasons to be discovered. If it's still empty after that, try shifting it a metre or two, or turning it a few degrees further towards the north. Small changes often make all the difference.