Pittosporum crassifolium

(previously known as Pittosporum crassifolium var. strictum...)

Karo

ABOUT:
Māori extracted a black dye from seeds.
The dark flowers give off a sweet scent on the night air.
Now naturalised in Hawaii and Norfolk Island, Karo is a recognised pest plant in some some parts of Australia’s Victoria and New South Wales.

IDENTIFY:     
5m high x 3m wide. This Pohutukawa look-alike is distinct in its clusters of crimson bell-shaped flowers appearing in spring through early summer. The loosely-striped upright multi-stemmed trunk supports dense leathery leaves with a felt-like layer on the underside. Green-white seed capsules split into 3 parts to reveal sticky black seeds in late summer through winter.

USE:
Kiwi natives cannot offer a tougher trimming species than this, performing well as a medium to large hedge. The dense leafy habit also makes it a great subject in screen plantings. Karo is very resilient in conditions of salt spray and high winds.
The root system of Karo can be utilised in binding loose soils and reducing erosion.

PLANT:
Protect plants from frost when young, and top young hedging plants when 30cm high to promote bushiness. Plants can be cut right back to old wood if required, as they readily re-establish a bushy habit.

Typical banded trunk

SIMILAR TO:     
Pohutukawa (Metrosideros excelsa) – 12m x 8m. Rough-barked, red powder-puff flowers. Multiple trunks emerging from base.
Ralph’s Kohuhu (Pittosporum ralphii) – 5m x 3m. Leaves are larger, darker green, and often with wavy edges. Seed capsule orange-yellow on inner surface.

ECOLOGICAL IMPORTANCE:     
Karo is host to the endemic Pittosporum Psyllid, which causes galls and yellowing on the leaves of young plants. The plant’s health is minimally affected.
It is also a favourite of the Pittosporum Shield Bug, which feeds on the unripe seed capsules.
The flowers of Karo provide nectar to insects and birds in spring through early summer, and the seeds  – produced in late summer through winter – appeal to birds as a food source.
The plant can be an urban weed through establishing easily where seeds have been dropped by native or exotic birds.

MORE INFO:
Plants for a Future – Pittosporum crassifolium
Taranaki Educational Resource – Karo
NZ Plant Conservation Network – Karo
The University of Auckland – Karo