Everything you need to know about bird boxes

Putting up bird boxes is a brilliant way to encourage birds into your garden. Habitat loss means there are fewer natural nesting spots these days. So the more we can do to help our feather friends, the better.

A child outdoors in a wooded area, reaching up to mount a wooden bird box to the trunk of a tree, surrounded by leafy green trees.

Which birds will use which type of box?

That depends on the type of box and the size of the nesting hole. As a rule:

A 25mm hole attracts smaller birds like blue tits and coal tits
A 32mm hole attracts birds like great tits and sparrows
A 45mm hole attracts bigger birds such as starlings and woodpeckers
Open-fronted boxes attract robins, wrens and pied wagtails
Specially shaped boxes attract swifts, swallows and house martins.

House sparrows nest in colonies, so cluster a few boxes together – like the sparrow wall in our Chelsea Flower Show garden.

Watch our video on how to help a bird

Four rusted metal-fronted bird boxes built into a stone wall, each with a round entrance hole.

Location, location, location

Before buying a nest box, have a look around your garden to make sure there's a good spot for it.
Protect birds from predators as well as sunlight, strong winds and driving rain – find a sheltered spot facing north or east.
Fix to a tree or the wall of your home – make sure there are bushes, trees or climbing plants nearby to provide cover.
Keep boxes away from cats and dogs by putting them 2 to 4m off the ground.
Open-fronted nest boxes need to be lower – around 1.5m. Hide them in vegetation like hedges, shrubs or thick creepers, to keep them safer from predators.
For woodpeckers, a box in a tree, 3 to 5m high, is ideal.
Make sure there's a clear flight path to all nest boxes (except open-fronted ones).

Eco-tip: Make sure your box is made from sustainable wood – look for the FSC timber mark or check out local sources.

Best time of year to put up a nest box

If you put up a nest box in autumn or early winter, a bird may roost in it over the cold months and then return to nest there in the spring.

Autumn clear out

Clean nest boxes once a year – but only in October and November, once birds have stopped using them. Put on gloves, take down the box, and remove any nesting material. Carefully wash out with boiling water then let it dry before putting back up.

Bird watch tip: Don't be tempted to check the boxes. Watch from a distance – or add a nest box camera before you install the box.