New Zealand holly

New Zealand holly: how do you recognise it?

Habit

Broad, evergreen shrub or small tree, about 3 m tall and wide in the garden.

Foliage

Holly-like, leathery and toothed, about 6–12 cm long; grey-green above, silvery white and felty beneath.

Flowers

Large heads of small white daisies with a yellow centre, in June–July.

Scent

Musky and heavy, especially on a warm day.

Roots

Fairly deep; it likes well-drained soil and dislikes wet feet.

Flowering: June–July · Plants: April–May · Pruning: April and July

Why grow it?

• Striking, holly-like foliage with a silvery white underside that shimmers in the wind.
• White flower heads with a musky scent in June–July: a magnet for bees.
• Excellent windbreak by the sea, even against salty wind.
• Evergreen: a dense, protective screen or hedge all year round.
• Tolerates dry soil and needs little care once established.
• Lovely as a specimen, as an evergreen backdrop or in an informal hedge.

New Zealand holly: where does it grow best?

• Sun or part shade; it flowers best in the sun.
• Well-drained soil: sand, loam or clay, acid to chalky, as long as the water can drain away.
• Dry to normally moist; avoid places where water stands in winter.
• Sheltered from cold, drying easterly winds; it does tolerate sea wind.
• Allow 2–3 m per shrub; for a hedge, plant at 1–1.5 m.

Light

Sun and partial shade

Soil type

Sand, loam or clay

Acidity

Not fussy

Moisture

Dry or normal

Size

3 m tall, 3 m wide

Hardiness

Half hardy (to -12 °C): protect it in harsh winters

Goes well with

• Hebe: Also from New Zealand, with the same sun and coastal setting.
• Ornamental grasses: Stems that sway in the wind, lovely in a coastal style.
• Lavender: Likes the same sun and dry soil; purple flowers next to the white heads.
• Hydrangea: Flowers later in summer and does well in seaside gardens.

New Zealand holly: when and how to plant it?

Plant in April–May.

1. Plant in April–May, so the shrub can root well before winter.
2. Dig a hole twice as wide as the root ball. In heavy clay, mix in sand or coarse grit for better drainage.
3. Set the plant at the same depth as in its pot and firm the soil well.
4. Leave 2–3 m between shrubs; in a hedge, 1–1.5 m.
5. Water thoroughly straight away, then weekly in dry weather during the first year.
6. Spread a layer of bark or wood chips around the base and tie a tall plant to a stake in its first year.

Care

Water

In the first two summers, water generously every week in dry weather. After that it is rarely needed.

Feeding

Compost or a handful of organic fertiliser in April. Do not overdo it: soil that is too rich gives soft shoots that are sensitive to frost.

Mulching

A layer of bark or leaf mould in November protects the roots from frost and drought.

Support

Give a tall young plant in a windy spot a sturdy stake for the first years.

Tip: Plant it sheltered from cold easterly wind and prune lightly after flowering. Tie a young plant to a stake in its first year.

New Zealand holly: when to prune it?

Pruning months: April and July.

When: Prune lightly straight after flowering, in July. Cut out frost damage only in April, when you can see which branches shoot again.

How:

• Shorten branches that are too long and the faded flower heads back to a healthy side shoot.
• Keep the shape loose and natural; spread a big prune over two years.
• In April, cut brown, frosted branches back to green wood.

Caution: Do not prune in late autumn or winter: new shoots and pruning wounds are then easily killed by frost.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Cuttings

From August to September: semi-ripe cuttings of 8–10 cm with a small heel of old wood, in a mix of sand and potting compost under plastic. They root slowly; overwinter them frost-free.

Seed

Sow in spring in seed compost under cover, barely covering the seed. It germinates slowly and unevenly.

New Zealand holly: how does it get through the winter?

Hardy to −12 °C: protect in harsh winters.

• Hardy down to about −12 °C: in Flanders only reliable in a sheltered spot.
• Keep it out of cold, drying easterly winds, for example against a sunny wall. In hard frost, cover it with horticultural fleece.
• Young plants get a thick layer of mulch around the base. In a pot, move them to a frost-free place.

Diseases and pests

• Frost damage: Brown, wilted leaves and branches after a hard winter. Wait until April to prune: it often shoots again from the base.
• Winter desiccation: Brown leaf edges in January–February caused by drying wind while the ground is frozen. A sheltered spot and a layer of mulch help.
• Root rot: Wilting, yellow leaves caused by soil that is too wet. Improve drainage or move it to a drier spot.
• Aphids: Small aphids on young shoots in spring. A jet of water is usually enough.

Through the year

• April: Plant. Cut out frost damage. Apply compost.
• May: Plant. Water after planting.
• June: Flowering begins: musky scent and bees.
• July: Flowering. Light pruning after flowering.
• August: Take semi-ripe cuttings. Water in dry weather.
• September: Take cuttings. Stake young plants firmly.
• November: Mulch against frost. Protect young plants.
• December: Rest. Cover in hard frost.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• The species name macrodonta means ‘large-toothed’ and refers to the toothed leaf edge.
• Although the leaves look like holly, it is not related to it: it belongs to the daisy family, like the sunflower.
• The silvery white underside of the leaves comes from a dense felt of tiny hairs.