A hedge is not a fence with leaves on it. Flail it flat every September and you get a tidy green wall that offers very little: no blossom for bees in May, no haws for redwings in January, no dense base for a hedgehog to shuffle along. Manage the same stretch of hawthorn, hazel and blackthorn with wildlife in mind and it will hold a surprising amount of life — usually for less work, not more. What follows is a practical checklist, season by season, for a hedge of any length, from a garden boundary to a field edge you walk twice a year.

Start with structure, not species

Most hedgerow wildlife needs shape more than it needs an unusual plant list. The valuable part of any hedge is the base: stems that branch near ground level, with leaf litter, tussocky grass and the odd bramble around them. Above that you want a slightly domed, uneven top that lets light down to the bottom. A flail that shaves the sides vertically and clips the top flat every year does the opposite, hollowing out the base and leaving bare earth underneath.

Signs of a hedge in good nick:

• Growth at ground level — stems branching within about 30cm of the soil rather than a bare, trunk-like mass.
• Flowers in spring and fruit in autumn, whether that is hawthorn, blackthorn, elder, dog rose or something else in your mix.
• Dead and decaying wood left in place rather than burned or cleared away.
• Patches of ivy and bramble, which give late nectar, winter cover and nesting sites.
• The occasional shrub or tree grown out to full height — roughly one hedgerow tree every 20 to 30 metres on a field boundary, where the site allows it.

Spring and early summer: hands off, eyes open

Between roughly March and August a hedgerow is working at full tilt: nesting birds, emerging invertebrates, the first flush of leaf. It is also the period when you should not cut. All wild birds, their nests and their eggs are protected while the nest is in use, and many agri-environment agreements rule out hedge cutting between 1 March and 31 August. Even without an agreement, put the flail away.

What to do instead:

• Walk the hedge slowly and note gaps, dead sections, bare ground and plants you cannot name.
• Check for nests before any strimming, fencing or work near the base, and stop if you find one.
• Mark hedgerow trees with a stake or a strip of flagging tape so they are not caught by the cutter next winter.
• Hold off on filling gaps. Bare-root planting is a winter job.

Late summer: survey, record, and leave things be

August into early September is the best time to assess what you have. Look for caterpillar damage on leaves, aphid colonies on new growth, droppings along the hedge base and the tell-tale runs of small mammals through the grass. Photograph the hedge from the same spot each year; it is the easiest way to see whether the base is thickening or thinning.

This is also when the temptation to tidy up is strongest, and when tidying does the most harm. Brown hairstreak butterflies, for example, lay their eggs on young blackthorn stems, where they overwinter on the twigs; cutting every bit of blackthorn in a single year removes them. Managing on a rotation, so some stems are always one to three years old, gets around the problem without any special effort.

Autumn: fruit, planning and the start of planting

Leave the berries alone. Hawthorn, blackthorn, holly, ivy and rose hips are the winter larder for redwings, fieldfares, blackbirds, thrushes and small mammals, and they are at their most useful in the lean weeks after Christmas. Cutting in October strips that food away just as the birds need it.

Autumn is for arranging things rather than doing them. Decide which third of the hedge you will cut this winter, order bare-root whips from a British nursery that sells native stock with known provenance, and book a contractor or a hedge-laying course early, because both fill up quickly. If the hedge is ancient or marks a field boundary, check whether the Hedgerow Regulations apply before you plan any removal, and if your land is in an agri-environment scheme, confirm the current cutting dates in your agreement first.

Winter: the cutting and laying window

Once the fruit has largely gone and the hardest weather has passed, usually from January into late February, the cutting window opens. Cut no more than a third of the hedge in any one year and leave the rest to flower and fruit, so there is always food and cover somewhere along the line.

1. Mark out your section. Rotate round the hedge so each part is cut every second or third year — never all of it in one go.
2. Set the cutter higher than feels natural. Light trimming on a long rotation suits most hedges better than a hard annual shave, and cutting into old, thick wood often gives poor regrowth.
3. Angle the sides so the hedge is wider at the base than at the top. Light reaches the bottom, and the base thickens up as a result.
4. Leave the top gently domed or slightly uneven. A flat top holds less fruit and looks worse for it.
5. Lift or step the machine round hedgerow trees and any thick, old stems you want to keep.
6. Do not clear the base. Leave the litter layer, and stack cut brash loosely at the field edge instead of burning it.
7. Leave one or two gaps if they are naturally there. Bramble quickly colonises them, and that scrub is excellent cover.

When to lay instead of cut

If a hedge has gone leggy, with long stems and a hollow, gappy base, another year of flailing will not fix it. Laying does: the stems are part-cut near the ground, bent over at an angle and woven together so the hedge regrows thick from the bottom up. Traditionally this is done between late autumn and early March, while the sap is down and before nesting begins. It is skilled work,

Photo: Mike Bird / Pexels