← All guides · Coastal species · Updated October 2026

How to prune an Olearia hedge: timing, technique and renovation for Broadstairs CT10.

Olearia is the shrub you plant on the boundary a metre from the clifftop edge above Joss Bay, where Escallonia would survive but might sulk in a hard nor'easter and Griselinia would need a season or two to find its footing. Daisy bush handles front-line salt blast better than almost any other hedging shrub, and its white daisy flowers in summer attract pollinators. Pruning it correctly means one central decision each year: have the flowers finished? Cut too early and you shorten the display; leave it until the plant has set seed in September and you push the trim uncomfortably close to the October dormancy point on one of the drier coasts in England. This guide gives the step-by-step method for the annual cut, the nesting check that comes first without exception, and the hard-renovation option for an Olearia that has grown too large or developed a leggy, open shape.

Steps

Step 1: Check for active nests before you lift any tool

Walk the full length of the hedge slowly before starting any work. Olearia's dense, fine-leaved canopy provides well-sheltered nesting sites and is used by blackbirds, robins, dunnocks and warblers throughout spring and summer. Watch for adult birds flying repeatedly into and out of the same section of the hedge, or listen for alarm calls and the faint sound of young birds from inside the canopy. On clifftop properties above Stone Bay, Joss Bay, Kingsgate and North Foreland, also scan the top of the hedge and any adjacent ground for signs of herring gull activity before cutting. If you find an active nest with eggs or young, mark the section with a cane and work around it. Return once the brood has fledged, which for most garden species takes three to five weeks from hatching.

Step 2: Time the cut by reading the flowering state

Olearia × haastii, the variety most commonly grown as a garden hedge, flowers from mid to late summer. The correct time to prune is after the flowering flush has clearly finished: when the white daisy flower clusters have browned and dropped their petals, and you can see fresh new extension growth pushing out from behind the spent clusters. In a typical CT10 season this point falls in mid to late August, though south-facing and sheltered hedges flower and finish earlier than north-facing or exposed clifftop ones.

Walk the hedge and read it directly: if more than half the flower clusters are spent and new lateral growth is visibly extending from the branch tips, the timing is right. If the hedge is still in active flower across most of its length, wait a week to ten days and check again. A cut two weeks too early loses the tail end of the display; a cut delayed to mid-October pushes the new growth from the trimmed tips into the start of the dormancy period and can reduce the following year's flowering on less vigorous plants.

Olearia macrodonta (New Zealand holly), which is also seen in older Broadstairs gardens as a large boundary shrub, flowers earlier, in June, and should be pruned in late June or July once its flowers are spent. O. scilloniensis, a May-flowering hybrid more often found in sheltered positions, should be pruned in late May or June, immediately after flowering.

Step 3: Gather your tools and lay a tarpaulin

Olearia's small leaves respond well to a powered hedge trimmer, unlike large-leaved species such as cherry laurel where trimmer blades slice rather than cut. A 45-55cm blade is well-suited to a typical boundary run. For finer detail near walls or gate pillars, switch to hand shears or secateurs. Also prepare:

• Loppers for any thick leaders or stems over 15mm diameter inside the canopy. Cut these at a node or branch junction, not mid-stem.
• Two canes and a length of taut garden twine for the string guide line on the top cut.
• A tarpaulin laid at the base before you start, to catch clippings without matting them into the lawn.

On clifftop gardens at Kingsgate and North Foreland, where Olearia is often the outermost boundary hedge, working into the prevailing wind increases debris scatter. Laying the tarpaulin on the leeward side of the hedge and working from the windward face reduces the time spent clearing up.

Step 4: Cut the sides in the batter angle, working from the base upward

Always cut the sides before the top. Start at one end and work the near face from base to top, angling the trimmer so the cut face leans slightly inward as you move upward: the hedge should be narrower at the top than at the base. On a 1.5m Olearia hedge, the top face should be roughly 80-100mm narrower on each side than the base. This batter angle is particularly important on front-line clifftop Olearia hedges in CT10, where the dominant north-east wind suppresses the upper and seaward growth. A hedge cut with vertical sides progressively loses light at the base, producing bare lower stems and a top-heavy silhouette that performs less well as a windbreak at ground level. The wider base holds foliage into the lower growth zone and deflects wind upward rather than channelling it under the hedge.

Remove approximately one-third of the current season's new growth from the sides. Olearia can tolerate cutting into older wood and will regenerate well, but the annual maintenance cut should take only the new extension growth: this keeps the hedge dense, maintains the batter profile built up over successive seasons, and avoids the extended brown-stub phase that follows a harder mid-season cut.

Step 5: Set a string line and cut the top level

Drive a cane at each end of the hedge, set the string line at the target cut height, and add a centre cane on runs over 5m to stop the line sagging. Cut along the string line with a steady pass from end to end. Olearia growth is not always uniform along a coastal run: the seaward face is typically denser and lower-growing than the sheltered side due to salt-wind suppression, so a string-line cut will tend to remove more from the sheltered side than the seaward side in any given year. This is correct, not an error: it keeps the top level and gradually brings the two faces toward the same finished height.

If any thick upright leaders project well above the string line, cut these with loppers before running the trimmer along the top: forcing the trimmer blade through a stem over 10mm diameter produces a torn, slow-healing cut rather than a clean one.

Step 6: Clear clippings and check the profile

Fold the tarpaulin inward and carry clippings to the green waste bin or the Kent County Council recycling centre in Margate (booking required). Olearia clippings compost readily in a reasonably active heap: the small, oval leaves break down faster than the leathery Escallonia or the resinous Leylandii. Step back to 5-6m and check the profile from the far side: the sides should read as a gentle A-shape, the top as a flat line. Note the finished dimensions for your records. A well-maintained Olearia haastii grows roughly 20-30cm per season once established, so the hedge will be back at the trimmed height by the following summer.

Renovation: hard cutting when the hedge has grown too large or too open

Olearia tolerates hard pruning better than most coastal evergreens. Where Escallonia has limits on how far back into old wood you can safely cut, and Leylandii will not regenerate from bare brown wood at all, Olearia will break freely from old stems if given the chance. This makes it a forgiving species to renovate.

For a hedge that has become significantly too tall, too wide, or open and leggy at the base, the renovation approach is to cut the whole plant back hard in late winter or early spring (February to March), before the new season's growth has pushed. Cut the top and sides back to 30-50cm below your target finished height and width: the plant will regrow by 20-30cm in the first season, reaching something close to the target by season two. Hard renovation at this time of year sits right at the start of the guidance nesting window (which opens on 1 March), so do it in February where possible and carry out the nest check at Step 1 regardless, particularly on south-facing sheltered hedges where birds sometimes nest early.

A less drastic option for a hedge that has simply grown wider than the available space is the one-in-three renovation cut: in early spring, cut back one-third of the oldest and thickest stems to near ground level while leaving the remaining two-thirds of the structure in place. This opens the interior to light, promotes basal regrowth, and the hedge continues to provide a screen throughout the renovation period. Repeat for two or three consecutive springs until the hedge has a dense, low-starting structure, then return to the annual post-flowering trim.

Olearia varieties in Broadstairs gardens and on the Thanet coast

Olearia × haastii (daisy bush) is the variety most widely available from UK nurseries and the one most commonly grown as a clipped hedge in Broadstairs gardens. It is a hybrid between two New Zealand species, has small grey-green leaves with white-felted undersides, and produces white daisy flowers in mid-summer. It holds the RHS Award of Garden Merit and stands up well to strong salt-laden winds, making it one of the few options that will perform directly on a clifftop boundary above Joss Bay or Kingsgate without requiring a shelter belt first. It reaches 1.5-2.5m with annual pruning and is hardy in most winters, including on exposed positions.

Olearia macrodonta (New Zealand holly) is a larger-growing species with holly-like leaves, silver-white undersides, and fragrant white flowers in June. It is most often seen in older Broadstairs and St Peter's gardens as a large informal screen rather than a clipped formal hedge, since it can reach 3-4m if left unpruned. It is more cold-tender than O. × haastii and can suffer stem dieback in a very hard winter with sustained easterly frost, particularly on north-east-facing clifftop positions. On properties directly above Stone Bay or the North Foreland cliffs I use O. × haastii in preference for a long-term formal hedge; macrodonta suits a sheltered garden boundary or a large informal screen in the more protected parts of St Peter's.

Common problems with Olearia hedges in CT10

Winter browning on the seaward face. In a hard winter combining frost and sustained north-east wind, Olearia can show tip browning or stem dieback on the exposed face. This is common on clifftop properties above Broadstairs and is not necessarily a sign that the hedge is dying. Leave the affected growth in place until April: the plant breaks from live wood behind the browned tips through spring, and once the recovery line is clear, cut back to the first healthy growth. In most cases full recovery is visible within a single growing season.

Failure to flower, or reduced flowering. Olearia flowers on growth produced in the previous season. If the hedge is cut in October or November rather than late August, the bud sites forming on the current season's new growth are removed before they can develop into next year's flower laterals. Switch to the post-flowering cut window described at Step 2, and flowering should recover within one to two seasons. Reduced flowering can also follow an exceptionally dry summer on shallow Margate Chalk: where the hedge is visibly drought-stressed in July and August, watering a recently planted or young hedge during the dry period will support both growth and flower development.

Bark splitting on the main stems after a hard frost. In a severe frost, the main stems of Olearia can show longitudinal splits in the outer bark. This looks alarming but is usually superficial: the cambium layer beneath the split is often intact, and the plant continues to grow normally. Monitor the affected sections through spring; if the stem fails to produce growth by June, it can be cut out at ground level and the plant will usually break from the base. This type of damage is rare on established hedges in sheltered CT10 positions, more common on clifftop plantings in their first or second winter.

Sources: Royal Horticultural Society, Olearia × haastii plant profile (rhs.org.uk); Burncoose Nurseries, Olearia plant notes (burncoose.co.uk); Royal Horticultural Society, "Pruning hedges" (rhs.org.uk/plants/types/hedges/pruning-guide); Wildlife and Countryside Act 1981, section 1; Birds of Conservation Concern 5 (BoCC5, December 2021) herring gull red-listing.