← All guides · Species · Updated October 2026

Olearia hedging on the Dover coast: exposure grade, pruning timing and species choice.

Olearia macrodonta, the New Zealand holly, holds an RHS Award of Garden Merit and is explicitly recommended as a hedging and windbreak plant for coastal areas. On the right site on the Dover coast it is a dense, fast-growing evergreen with summer flowers and genuine clifftop credentials. The difference between a hedge that thrives and one that struggles maps closely onto which species from within the olearia genus you choose, and where in the exposure gradient your garden sits.

What olearia is and why it matters on the Dover coast

Olearia is a genus of evergreen shrubs and small trees native to Australasia, primarily New Zealand and Australia. The species used for UK coastal hedging are the hardier New Zealand forms, of which macrodonta, traversii and x haastii (a hybrid) are the three most widely grown in British gardens. Olearia macrodonta carries the name "New Zealand holly" because its dark green leaves with their pale undersides and slightly toothed edges resemble holly foliage, though the plants are not related. The RHS gave it an Award of Garden Merit and describes it as suitable for use as a hedging plant or windbreak, especially in coastal areas.

The reason olearia works on coastal sites is partly structural. Its leaves are small to medium-sized, firm and leathery: characteristics that help them shed salt spray without retaining it against the leaf surface in the way that softer or larger-leaved species do. This is a similar mechanism to griselinia and escallonia: the architecture of the foliage matters as much as any intrinsic salt chemistry. A well-established O. macrodonta hedge on a moderately exposed Bay-facing garden boundary comes through a November Channel gale with no visible damage beyond the outermost shoot tips; a photinia hedge in the same position would show significant browning on its seaward face. For the full comparison of where olearia, escallonia, griselinia and elaeagnus sit relative to each other at each exposure level, see our salt-wind resilient species guide.

Olearia also carries a practical advantage that is easy to overlook: the flowers are produced on current and previous season's growth, which means a hedge that is pruned at the right time will still flower reliably every summer. A flowering hedge on a coastal boundary is not merely a visual bonus; it provides nectar for pollinators at a time of year, July and August, when other boundary species have finished. The white daisy-type flowers are produced in flat-topped clusters and are strongly attractive to hoverflies, bees and butterflies, making olearia a reasonable choice if wildlife value is part of the brief alongside shelter and screening.

Species choice across the exposure gradient

Olearia macrodonta is the first name on the list for clifftop and Bay exposure. The species is native to the South Island of New Zealand, including coastal ranges, which gives it the salt-wind tolerance it carries in UK conditions. The characteristic silver-white undersides to the leaves are a field identification point: the leaves look darker above and pale beneath, giving the hedge a two-tone effect when the wind catches them. Its maximum height in UK cultivation is typically 3 to 4 metres without regular cutting, and under maintenance as a hedge it stays at whatever height is useful. Burncoose Nurseries, a Cornish specialist with long experience of coastal and wind-exposed planting, includes macrodonta, traversii and x haastii among the olearia forms it recommends for hedges and windbreaks in coastal areas.

Olearia traversii is worth mentioning separately because it has an even stronger reputation for salt tolerance and windbreak performance than macrodonta on the south-west England and Irish coasts, where it is widely used as a garden boundary and windbreak species. It has a slightly different leaf shape, longer and narrower than macrodonta, and it is not as widely stocked in mainstream UK garden centres, though specialist coastal nurseries carry it. On gardens directly facing the South Foreland or the open Channel at the most exposed clifftop positions, it is the form to ask for specifically if macrodonta is unavailable or if the planting is intended as the seaward front row of a windbreak rather than a formal hedge behind it.

Olearia x haastii is the hybrid most commonly available from UK garden centres and hedging suppliers. It is smaller-growing than macrodonta, typically 1.5 to 2.5 metres when maintained as a hedge, and it has a rounder, more compact habit. The flowers are freely produced in July and August. At village-level exposure in St Margaret's at Cliffe, in Kingsdown back from the cliff edge, and in the Walmer and Deal corridor, it is a straightforward recommendation: salt air is present but manageable, chalk soil suits it, and its compact habit makes formal maintenance easier than macrodonta's more vigorous growth.

One practical caveat that applies across all three: olearia is not reliably hardy in every UK winter. The RHS hardiness rating for macrodonta is H4, meaning it is generally hardy to about -5 to -10℃. On the Dover coast, winter minimum temperatures rarely fall below -6 to -7℃, which keeps macrodonta within range in most years. The risk comes from a specific combination: a hard easterly frost arriving after a mild, late-growing autumn, when the plants have not hardened off as they would in an earlier cold spell. On the most exposed clifftop gardens above St Margaret's Bay, this is worth bearing in mind when deciding whether to plant macrodonta as the seaward-facing front row or whether a more reliably winter-hardy species such as elaeagnus or hawthorn is the right choice for that specific exposed face.

Clifftop and Bay: what establishment requires

The RHS guidance for olearia is explicit that it performs best when planted in spring, allowing a full growing season before the first winter. On the chalk clifftop above St Margaret's Bay and at Kingsdown along the exposed sections, this matters: a plant that goes into the ground in November without an established root ball faces the first winter in an underrooted state on free-draining chalk and may dry out from the roots up before any visible frost damage appears. Spring planting, from late April through to late May, gives the root system several months to establish in the chalk before autumn arrives.

Container-grown stock is strongly preferred over bare-root for clifftop olearia. Olearia is not routinely available bare-root in the way that hawthorn, blackthorn or hornbeam is; most suppliers stock it in containers. The container root ball provides better anchorage going into the first autumn, which on an exposed clifftop site reduces wind rock to a manageable problem rather than a persistent one. Staking with two canes crossed behind the stem, or a single stout post with a rubber tie, is standard practice at Bay and clifftop exposure: gale-force autumn winds test the anchorage of a newly planted container olearia, particularly on shallow chalk where stake penetration is limited. For the soil preparation technique on the chalk geology around St Margaret's, Kingsdown and Ringwould, our chalk-soil hedge establishment guide covers the full method.

A temporary windbreak net on the seaward face during the first winter is worth considering on the most exposed clifftop positions, particularly on the South Foreland headland. The standard polypropylene woven mesh, the same material used for bare-root windbreak plantings, provides enough protection to reduce desiccation on the windward shoots without preventing the plant from developing wind-hardness. Remove it in spring rather than leaving it in place through the second growing season. Our windbreak hedge design guide covers the full mechanics of temporary wind protection and the establishment sequences that suit clifftop sites.

Pruning timing and the nesting-season window

Olearia macrodonta and x haastii flower in June and July. The correct annual maintenance prune is after the flowers fade, in late July or early August. Cutting before flowering removes the flower buds; cutting in autumn or winter removes the season's new growth and leaves the hedge without next summer's flowers. Late July is the timing we use at St Margaret's: the flowers are finished by then, the hedge still has enough of the growing season ahead to put on a small amount of further growth before autumn, and you are ahead of the autumn Channel gales that can make hedge work awkward in September and October.

This places the main pruning window within the period governed by the Wildlife and Countryside Act 1981, section 1. The Act makes it a criminal offence to damage or destroy an active wild bird's nest. The main nesting season closure runs from 1 March to 31 August. Late July cutting, when olearia is at its ideal pruning window, falls within that closure. On a hedgerow with dense foliage, late-breeding species including goldfinch, linnet and whitethroat can have active nests through into August along the Dover coast. We carry out a visual inspection before any cut in this period and will hold off if active nests are present. If you are doing this yourself, the safe and legal position is to check the hedge thoroughly before starting: any active nest found means the cut waits until after 31 August. The full guide to nesting-season timing and how Channel gale patterns affect the September cutting window is in our hedge cutting timing guide.

A light February tidy is the second pruning operation: remove winter-damaged tip growth, correct the outline and do nothing structural. Olearia regenerates well from old wood if harder renovation pruning is needed, but this is better done in late winter rather than autumn: cutting back to old wood in autumn leaves the wound exposed to winter frost, whereas a late February cut allows spring regrowth to close over the cuts quickly. For a severely overgrown olearia that has lost its hedge shape, a staged renovation over two to three years (one side per year) is kinder than a single hard cut, particularly on clifftop sites where the hedge is the garden's main wind shelter and a complete cut-back leaves the interior exposed in its most vulnerable state.

Village and sheltered sites: the maintenance picture

In St Margaret's at Cliffe village, in Kingsdown's inland streets, in Ringwould and through the Walmer and Deal corridors, olearia x haastii is as close to a straightforward recommendation as most hedging species gets in this part of Kent. It establishes without wind-protection drama in most village gardens, grows at a consistent 30 to 40 centimetres per year on the chalk, and one cut a year in late July or early August, once the flowers have faded, keeps it tidy and correctly shaped. A second light trim in February is enough for a well-maintained hedge that is already at the right height and is not being pushed for formal precision.

In sheltered Dover town gardens, the main consideration shifts to variety and purpose. The more ornamental olearia forms are realistic options here, and a gardener who wants a less vigorous hedge with a slightly different flower timing or leaf shape has a wider choice from within the genus. The key point on chalk soil that applies across the whole coverage area is that olearia is tolerant of free-draining alkaline conditions: it does not need the pH adjustment that ericaceous species such as rhododendron would require on the same ground, and it is comfortable in the fast-draining chalk profiles that run from the St Margaret's clifftop through to the inland gardens at Ringwould and Whitfield, north of Dover.

One note on maintenance tools: olearia's small, firm leaves do not suffer the cut-leaf browning that makes rotary hedge trimmers unsuitable for cherry laurel. A standard hedge trimmer, electric or petrol, gives a clean finish and the regrowth from each cut is even. The foliage recovers quickly and the seaward face of the hedge typically shows no browning after a clean trim, unlike species with larger or more tender leaves.

Sources: Royal Horticultural Society, Olearia macrodonta plant profile (RHS Award of Garden Merit; described as suitable for use as a hedging plant or windbreak, especially in coastal areas; hardiness H4; pruning group 9); Burncoose Nurseries, olearia species guidance (macrodonta, traversii and x haastii recommended for coastal hedging and windbreaks in coastal areas); Hayloft Plants, olearia growing guide (spring planting, coastal exposure, pruning timing after flowering); Wildlife and Countryside Act 1981, section 1 (nesting season, offence to damage or destroy an active nest, 1 March to 31 August). Place names verified: St Margaret's at Cliffe (CT15, OS grid TR374448), St Margaret's Bay (CT15), South Foreland (CT15), Kingsdown (CT14), Ringwould (CT14), Walmer (CT14), Deal (CT14), Dover (CT16/CT17), Whitfield (CT16, north of Dover).