Autumn is the season to do less

For most of the year a wildlife garden asks something of you. You sow, you water, you deadhead, you stake. Autumn is different. Between now and the first hard frosts, the most valuable thing you can do is resist the urge to tidy up. Seed heads, fallen leaves, hollow stems and slowly rotting wood are the winter larder and shelter for everything from goldfinches to ground beetles, and they cost you nothing but a little restraint.

Whether your plot is a windswept strip of coastal garden or a sheltered inland square, the principles are the same. A little purposeful mess now pays you back handsomely when the queen bumblebees wake up next February.

Leave the seed heads standing

Resist the secateurs for a few more months. Plants that have finished flowering are still working hard: their seed heads feed birds right through the lean months, and their hollow stems shelter overwintering insects. Teasel is the classic example — goldfinches will cling to the prickly heads well into winter, teasing out the seed. Knapweed, field scabious, wild carrot, yarrow and bird's-foot trefoil all earn their place too, and linnets, siskins and tits will work through them in turn.

• Delay cutting back until late February or early March, when the worst of the weather has passed and insects have stirred.
• Cut only half the border each year, so there is always standing structure and a seed crop somewhere.
• Leave stumps of 30–45cm on hollow-stemmed plants such as teasel and fennel — solitary bees and other small insects tuck themselves inside them to overwinter.
• Skip the deadheading from September onwards and let the garden go to seed deliberately.

Build a log pile for beetles and bees

Dead wood is one of the scarcest habitats in a modern garden, and one of the richest. A simple stack of untreated logs in a shady corner will be colonised by fungi, beetles and the larvae that feed on them. Stag beetle larvae spend years inside decaying timber, and lesser stag beetles, ground beetles and woodlice all appreciate the damp, dark spaces between the logs.

Use native broadleaf wood if you can — oak, ash, beech or apple — and keep it untreated. A pile roughly 60cm high, with the largest logs at the bottom and some partly buried in the soil, holds moisture better and stays cooler in summer. Add a few hollow canes or a bundle of cut stems alongside, and you have made a home for solitary bees as well. Site it somewhere out of the strongest wind and leave it undisturbed for years; the value of a log pile grows with time.

Let fallen leaves feed the soil

Raking every leaf into a bag and sending it away is a small act of vandalism. Leaf litter is the beginning of a food chain: it feeds worms, millipedes, springtails and fungi, which in turn feed the blackbirds and thrushes that toss the leaves about looking for a meal.

A thin layer of leaves on borders is ideal — it insulates the soil, suppresses weeds and slowly breaks down into humus. Under trees and shrubs, leave the leaves where they fall. On the lawn, a scattering is harmless, but thick drifts will smother the grass, so move those onto the beds instead.

Anything left over can be turned into leaf mould. Fill a wire bin or a few old compost bags punched with holes, keep them damp, and leave them for a year or two. The result is a dark, crumbly, low-nutrient material that is perfect for mulching coastal beds, where sandy soils drain fast and lose goodness quickly.

Plant spring bulbs now

Autumn's one genuinely active job is planting. Spring bulbs are the first proper nectar of the year, and they matter enormously to queen bumblebees emerging from hibernation in February and March.

• Native daffodil (Narcissus pseudonarcissus) — smaller and later than the garden varieties, and far better for insects.
• Snowdrops and winter aconite — reliable early sources of pollen, even in a cold snap.
• Snake's head fritillary — lovely in damp grass or a border that does not dry out.
• Native bluebell — plant bulbs rather than importing anything you cannot identify, and never the Spanish bluebell.

Plant bulbs at roughly three times their own depth and set them out in loose drifts rather than neat rows. Group them around the base of deciduous shrubs and in rough grass, where their foliage can die back undisturbed.

Coastal gardens: work with the wind

On the coast, autumn tasks come with added salt and wind. Choose plants that expect it. Sea thrift, sea campion, sea lavender, viper's bugloss, yellow horned-poppy and the beautiful sea holly are all adapted to exposure, and their seed heads and flowers serve coastal insects perfectly. Spring squill, a tiny native bulb of clifftops and short turf, is a lovely choice for a sunny, well-drained spot.

A shelter belt makes everything else possible. Plant a loose hedge of native shrubs — hawthorn, blackthorn, sea buckthorn or elder — a couple of metres back from the boundary, and it will filter the wind without creating a damaging blast on the far side. Mulch generously with leaf mould or spent compost to hold moisture in sandy soil.

One advantage of coastal sites is that they often stay mild well into December, which stretches your planting window. Use it. Get the bulbs in, stack the logs, and then step back and let the garden look after itself.