Koromiko

Koromiko: how do you recognise it?

Habit

Loose, wide shrub up to about 2 m high and 2 m across, with upright to arching branches.

Leaves

Long, narrow and lance-shaped, willow-like, pale to mid green; evergreen.

Flowers

Long, slender spikes of small white to pale lilac flowers, from July to September.

Roots

Fibrous and fairly shallow: it likes moisture-retentive but well-drained soil.

Origin

New Zealand and southern Chile.

Flowering: July–September · Plants: April–May · Pruning: April

Why grow it?

• Long white flower spikes from July to September, an excellent plant for bees and butterflies.
• Evergreen, narrow leaves that give a light, soft green accent all year.
• Grows into a large shrub, beautiful as a specimen or at the back of a sheltered border.
• Flowers for a long time, into autumn, when many other shrubs have finished.
• Tolerates wind and coastal climates better than many shrubs.

Koromiko: where does it grow best?

• Full sun to half shade; in sun it flowers best.
• Free-draining, humus-rich soil: sand, loam or light clay, acid to chalky.
• Evenly moist to normal; not too dry in summer and not waterlogged in winter.
• Sheltered from cold easterly winds and hard frost, preferably against a south-facing wall.
• Allow 1.5–2 m per plant.

Light

Sun and partial shade

Soil type

Sand, loam or clay

Acidity

Not fussy

Moisture

Normal

Size

2 m tall, 2 m wide

Hardiness

Half hardy (to -10 °C): protect it in harsh winters

Goes well with

• Lavender: Same sunny, free-draining spot; scented purple flowers.
• Stonecrop: Flowers at the same time, in August–September, and also attracts butterflies.
• Ornamental grasses: Light plumes that go well with the airy spikes.
• Cranesbill: Blue to purple flowers at the foot of the shrub.
• Roses: A white hebe behind a rose bed brings calm.

Koromiko: when and how to plant it?

Plant in April–May.

1. Plant in April–May, when the worst frosts are over, so the plant can root well before winter.
2. Dig a hole twice as wide as the root ball; mix in compost and, on heavy soil, a little sand.
3. Set the plant at the same depth as in its pot and firm the soil well.
4. Leave 1.5–2 m between plants.
5. Water in thoroughly and keep the soil slightly moist in the first year.
6. Lay a layer of bark or leaf mould around the base, without covering the stems.

Care

Water

In the first year during dry weather, afterwards plenty of water at the base in dry summers. In pots regularly, but never with wet feet.

Feeding

In April a handful of organic fertiliser or shrub feed; not after August.

Mulching

A layer of bark or leaf mould in spring keeps the soil moist and protects the roots in winter.

Spent flowers

Cut off the spikes after flowering: the shrub stays neater.

Support

In a windy spot a stake or support helps keep the long branches upright.

Tip: Plant it against a sheltered south wall and pile leaves around the base in October. In spring, wait before cutting out brown branches until you can see which have survived the winter.

Koromiko: when to prune it?

Pruning months: April.

When: In April, when the risk of frost is over and new shoots start to grow.

How:

• Cut dead and frost-damaged branches back to healthy wood, which is often only clearly visible in May.
• Trim the shrub lightly, about a third of the young shoots, just above a few leaves.
• Remove spent flower spikes in autumn or spring.
• An older plant can be renewed over a few years by shortening a few branches a little harder each time, within green wood.

Caution: Do not prune in autumn: it encourages soft shoots that are killed by the first frost. Do not cut deep into old, bare wood either.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Semi-ripe cuttings

In July–September take cuttings of 8–10 cm from non-flowering shoots, strip the lower leaves and insert in sandy compost. Usually rooted in 3–5 weeks.

Seed

Possible, but cultivars do not come true from seed; cuttings are the reliable method.

Koromiko: how does it get through the winter?

Hardy to −10 °C: protect in harsh winters.

• Moderately hardy, to about −10 °C: usually fine on the coast and against a sheltered south wall, but it can freeze in hard winters inland.
• In October pile leaves or straw around the base and wrap young plants in fleece during hard frost.
• In a pot: move it frost-free for winter, to a bright, cool place, and water sparingly.

Diseases and pests

• Frost damage: Brown leaves and dead branches after a hard winter. Wait until May, then cut back to healthy wood; it often regrows from the base.
• Root rot: The plant fades and drops leaves on soil that is too wet. Improve drainage with sand or plant on a slight mound.
• Leaf spot: Brown or black spots on the leaves, especially in wet spells. Remove affected leaves and avoid watering over the foliage.
• Sagging branches: Long branches bend over after rain or wind. A support and a light trim in spring help.

Through the year

• April: Planting. Prune and remove dead branches. Feed.
• May: Planting. Cut out frost damage.
• June: Water in dry weather.
• July: Flowering begins. Cuttings from late July.
• August: Full flower, plenty of butterflies. Take cuttings.
• September: Last flowers. Take cuttings.
• October: Lay mulch or leaves around the base.
• November: Move pots frost-free. Protect young plants.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Butterflies

Nectar for butterflies.

Did you know?

• ‘Koromiko’ is the Maori name of this plant; the species name salicifolia means ‘willow-leaved’.
• It grows naturally in New Zealand and in southern Chile.
• Hebes were long treated as a genus of their own, but are now placed in Veronica (speedwell).