Kohuhu

Kohuhu: how do you recognise it?

Habit

Upright, dense shrub 2–3 m tall and about 2 m wide; left unpruned, sometimes a small tree.

Leaves

Small, oval, 2–6 cm, with a very wavy edge; light green, variegated or purple, evergreen.

Twigs

Dark purple-brown to almost black, a lovely contrast with the leaves.

Flowers

Small, dark purple bells among the leaves, in April–May.

Scent

Sweet, like honey, especially in the evening.

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

Why grow it?

• Fresh, wavy leaves on dark twigs all year round: a fine structural plant.
• Takes clipping well: as a shaped shrub, an informal hedge or in a large pot.
• The small flowers smell sweetly of honey in the evening.
• The stems make beautiful cut foliage for bouquets.
• Tolerates sea winds well and is popular in coastal gardens.

Kohuhu: where does it grow best?

• Sun or light partial shade; variegated and purple varieties colour best in sun.
• A sheltered spot, out of cold east and north winds, for example against a wall or among other shrubs.
• Well-drained sandy or loamy soil, acid to neutral, that does not dry out but does not stay wet either.
• Allow 1.5 m as a specimen, 50–60 cm between plants for a hedge.

Light

Sun and partial shade

Soil type

Sand or loam

Acidity

Acid or neutral

Moisture

Normal

Size

3 m tall, 2 m wide

Hardiness

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

Goes well with

• New Zealand flax: Bold, sword-shaped leaves beside the fine, wavy foliage.
• Ornamental grasses: They move in the wind, a lovely contrast with the dense shrub.
• Lavender: A silvery-grey, fragrant base in the sun.
• Hydrangea: Large flowers against the calm, evergreen backdrop.

Kohuhu: when and how to plant it?

Plant in April–May.

1. Plant in April–May, so it can root in before winter.
2. Dig a hole twice as wide as the root ball; on heavy soil, mix in some coarse sand.
3. Set the plant at the same depth as it was in the pot and firm the soil.
4. Water in well and mulch the base with compost or wood chips.
5. In a pot: choose a roomy pot with a drainage hole, a drainage layer and compost for shrubs.

Care

Water

In dry spells for the first few years. In a pot regularly, but never leave it standing in water.

Feeding

A little compost in spring is enough; in a pot, some feed for evergreens from April to July.

Mulching

A mulch keeps the roots moist in summer and protects them in winter.

Repotting

Move potted plants into a slightly larger pot every two or three years in spring.

Tip: Plant it in shelter against a wall or among other shrubs, as it can be cut back in cold winters. Wait until April to prune, when you can see what has survived the winter.

Kohuhu: when to prune it?

Pruning months: April.

When: In April, once the worst frosts are over and you can see which parts have survived the winter.

How:

• Cut frosted parts back to healthy wood.
• Keep it in shape or clip it as a hedge; it takes clipping well.
• On variegated varieties, remove shoots with all-green leaves.

Caution: Don’t prune in autumn: the new shoots would not have time to harden off before winter.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Semi-ripe cuttings

In July–August, 10 cm cuttings in a sandy cutting mix under plastic. Overwinter them frost-free.

Seed

Seed of the species can be sown indoors in spring; varieties do not come true from seed.

Kohuhu: how does it get through the winter?

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

• Hardy to about −10 °C: it can be cut back by frost in cold Belgian winters.
• Protect it with horticultural fleece in hard frost and mulch the base.
• In a pot: move it to a cool, light room, or wrap the pot well against a sheltered wall.
• A frost-damaged plant often regrows; wait until spring before giving up on it.

Diseases and pests

• Frost and wind damage: Brown leaves and dead twigs after a cold winter or in east winds. Cut back to healthy wood in April.
• Root rot: On wet soil or in a pot without drainage: the plant wilts. Make sure the soil drains well.
• Scale insects: Brown scales and sticky leaves. Rub them off with a soft brush.
• Aphids: On the young shoots. Spray them off with water.

Through the year

• March: Remove the fleece as the weather turns milder.
• April: Prune and shape. Plant. Flowering begins.
• May: Flowering with a honey scent. Plant.
• June: Water in dry spells, especially in pots.
• July: Take semi-ripe cuttings.
• August: Take semi-ripe cuttings. Water in dry spells.
• November: Mulch the base. Protect potted plants.
• December: In hard frost, drape fleece over the shrub.

Did you know?

• The small, dark purple flowers are easily overlooked, but give off a sweet honey scent in the evening.
• The name Pittosporum means ‘pitch seed’: the seeds are coated in a sticky, resinous slime.
• The fine, wavy foliage is widely used as cut greenery in bouquets and flower arrangements.