<i>Pittosporum tenuifolium</i>(Pittosporum tenuifolium) hero image

Kōhūhū

Pittosporum tenuifolium

Not specified

This native plant, known as Pittosporum tenuifolium (scientific name: Pittosporum tenuifolium ), is a remarkable species endemic to New Zealand. It is characterized by its unique features, ecological role, and cultural significance. This comprehensive guide provides detailed information on its care, propagation, and importance within the New Zealand ecosystem. Understanding this plant contributes to the appreciation of our rich biodiversity and heritage, and supports conservation efforts for Browse All .

<i>Pittosporum tenuifolium</i>(Pittosporum tenuifolium) showing <i>Pittosporum tenuifolium</i>growth habit
Image credit: Kōhūhū (Pittosporum tenuifolium) - photo by Wikipedia contributors, via Wikipedia

Plant Description

Identification and Physical Characteristics

Kōhūhū ( Pittosporum tenuifolium ), also known as black matipo or kohukohu, is an evergreen shrub or small tree native to New Zealand Discover more about native ferns. It can grow up to 8-10 meters tall, though many cultivated varieties range from 1 to 4 meters. It has attractive, often shiny, wavy-edged leaves that can be variegated and come in shades of purple, yellow, green, or silver-grey. The Latin name "tenuifolium" means "slender-leaved" or "thin-leaved." Young leaves may have fine hairs, while adult leaves are smooth and glossy. The stems are typically dark, ranging from gray to nearly black on young shoots. Small, dark reddish-purple to almost black flowers appear from late spring to early summer. These flowers are often inconspicuous but are highly scented, especially at night and in damp conditions, giving off a honey-like fragrance that attracts moths. Fertilized flowers develop into small, globe-shaped fruits that turn almost black and split open when ripe, revealing seeds encased in a sticky fluid.

Quick Facts

Pittosporum tenuifolium quick facts
Scientific Name Pittosporum tenuifolium
Height 6-10 m
Spread 3-6 m
Water Needs Moderate
Light Sun to partial shade
Frost Tolerance Hardy once established
Salt Tolerance Moderate; tolerates coastal conditions
Growth Rate Fast growing
Lifespan Long-lived

Climate Best Suited to

Pittosporum tenuifolium is well adapted to various New Zealand regions.

Regional Suitability

City suitability for Pittosporum tenuifolium
City Climate Suitability
Auckland High
Wellington High
Christchurch Medium

Plant Habitat

Natural Occurrence and Ecology

Kōhūhū ( Pittosporum tenuifolium ), also known as black matipo or kohukohu, is an evergreen shrub or small tree native and endemic to New Zealand. It is widely distributed across both the North and South Islands, thriving in a variety of habitats from coastal areas to lower mountain forests, reaching altitudes up to 900 meters (nearly 3000 feet).Forest Margins and Clearings:It is commonly found in forest margins, regenerating areas, and open woodlands, where it benefits from varied light conditions.Well-Drained Soils:Kōhūhū prefers light and well-drained soils. While it can tolerate poor conditions, including less fertile soils and droughts, it does not thrive in areas with damp conditions, such as the West Coast of New Zealand, as this can lead to winter leaf drop.Coastal and Inland:This hardy plant can tolerate coastal winds and is found in both coastal and inland environments, showcasing its adaptability.Widespread:Its widespread distribution throughout New Zealand highlights its ecological flexibility and ability to adapt to diverse climatic conditions.Successional Habitats:It is often found in successional habitats, playing a role in the natural regeneration of forests.The presence of Pittosporum tenuifolium in these diverse habitats underscores its ecological importance in contributing to the biodiversity and structural complexity of New Zealand's native forests.

Growing Requirements

Soil Requirements

Prefers well-draining soil rich in organic matter.

  • Well-drained
  • Loamy

Light Requirements

Grows best in partial to full sun.

  • Full Sun
  • Partial Shade

Water Requirements

Requires regular watering during dry periods.

  • Regular
  • Drought tolerant once established

Planting and Establishing

Establishment Guidance

Plant Pittosporum tenuifolium in a hole twice the width of the root ball.

Proper establishment is key to long-term success. Ensure the planting hole is twice as wide as the root ball and backfill with a mix of native soil and organic compost. Initial watering should be thorough, followed by regular monitoring during the first two growing seasons to ensure the plant becomes well-anchored and resilient to local climate fluctuations.

Ecological Role

Biodiversity and Ecosystem Impact

Provides habitat and food for native fauna.

This species plays a vital role in its local ecosystem, providing essential habitat and food sources for native biodiversity. Its presence supports complex ecological interactions, contributing to the overall health and stability of the environment. By planting this native, you help maintain the intricate web of life that defines New Zealand's unique natural heritage.

Uses & Significance

Garden Uses

Ideal for rock gardens and native borders.

  • Rock gardens
  • Ground cover

Ecological Value

Supports local pollinators.

  • Birds
  • Insects

The versatility of this plant makes it a valuable addition to many New Zealand gardens. Beyond its aesthetic appeal, it offers practical benefits such as soil stabilization and shelter for smaller plants. Its historical and modern uses highlight its enduring importance in both traditional practices and contemporary landscape design, making it a thoughtful choice for any restoration or gardening project.

Landscaping Uses

Adds texture and form to modern landscapes.

In a landscape setting, this plant provides excellent structure and year-round interest. Its unique form and foliage can be used to create focal points or as a cohesive element in a larger native planting scheme. It pairs well with other New Zealand natives, allowing for the creation of diverse and resilient garden environments that reflect the natural beauty of Aotearoa.

Seasonal Care Calendar

Spring

Mulch and apply balanced fertilizer.

  • Fertilize
  • Mulch

Summer

Water deeply during dry spells.

  • Water
  • Check for pests

Autumn

Tidy up any dead foliage.

  • Prune lightly
  • Plant new specimens

Winter

Protect from heavy frosts if necessary.

  • Frost protection

When to Prune and How Much

Minimal pruning required to maintain shape.

  • Remove dead branches

Always use clean, sharp tools.

Regular maintenance through careful pruning ensures the plant remains healthy and maintains its desired shape. Focus on removing dead or diseased wood to promote better air circulation and prevent the spread of pathogens. Proper pruning techniques help the plant direct its energy toward new growth, resulting in a more robust and aesthetically pleasing specimen in your garden.

How to Grow Kōhūhū

Cultivating Pittosporum tenuifolium ( Pittosporum tenuifolium ) is a rewarding endeavor for any gardener interested in New Zealand's unique flora. This species can be propagated through several methods, each requiring specific conditions to ensure healthy growth and establishment. Successful propagation depends on mimicking the plant's natural environment and providing consistent care during the early stages of development.

From Seed

Propagation from seed is often the most effective way to produce a large number of Pittosporum tenuifolium plants. Seeds should be collected when they are fully mature. Freshly collected seeds generally have higher germination rates than those that have been stored for long periods.

Sow fresh seeds in a seed-raising mix.

  1. Collect seeds
  2. Sow in trays

Keep moist until germination.

From Cuttings

For those wishing to replicate specific characteristics of a parent plant, vegetative propagation via cuttings is the preferred method. This technique ensures that the new plants are genetically identical to the source. Semi-hardwood cuttings taken during the appropriate season usually yield the best results for this species.

Take semi-hardwood cuttings in late summer.

  1. Take cuttings
  2. Use rooting hormone

Additional Methods

Depending on the growth habit of Pittosporum tenuifolium , other methods such as division or layering might also be viable options. Division is particularly suitable for plants that form dense clumps or have spreading root systems, while layering can be used for species with trailing or flexible stems.

Division can be done in early spring.

  1. Divide clumps
  2. Replant immediately

Pests & Diseases

Generally resistant to major pests.

While generally resilient, maintaining optimal growing conditions is the best defense against pests and diseases. Regular monitoring allows for early detection of any issues, which can often be managed through cultural practices or organic interventions. Ensuring good air circulation and appropriate watering will significantly reduce the plant's susceptibility to common environmental stresses and pathogens.

Cultural Significance

Pittosporum tenuifolium , commonly known as kōhūhū, black matipo, kohukohu, or tawhiwhi, holds significant cultural importance, particularly among the Māori people of New Zealand, its native land.Traditional Māori Uses:The Māori people traditionally utilized various parts of the kōhūhū plant. The resin and oils extracted from its leaves were highly valued for their scent and were often mixed with ingredients from other native trees to create perfumes. These scented oils were used to fragrance small pouches, the skins of dead birds worn around the neck, and to scent the homes and mats of high-ranking individuals. The wood of the Pittosporum was also fashioned into weapons and utensils.Medicinal Properties:Kōhūhū was incorporated into traditional Māori medicine to treat various ailments, with studies supporting its antimicrobial properties.Ceremonial Role:The leaves and branches of kōhūhū played a role in sacred Māori ceremonies, including baptisms. Today, they are still used in welcoming ceremonies for visitors to a marae (a Māori meeting place), a practice reflected in its Māori names tāwhiri ("to wave to") and rautāwhiri ("to wave a leaf").Ecological Value:Beyond its direct human uses, kōhūhū is ecologically significant in New Zealand, supporting native biodiversity and contributing to habitat structure. It is valued in restoration efforts and garden plantings, with its flowers attracting native birds and beneficial insects.Historical Navigation:Anecdotally, European sailors are said to have used Pittosporum as a landmark for navigation during their voyages.In modern horticulture, Pittosporum tenuifolium is a popular garden plant both in New Zealand and internationally. It is widely used for hedging, topiary, shelter belts, and as a specimen plant due to its adaptability, rapid growth, and tolerance for pruning. Its distinctive dark bark, fine-textured foliage, and various cultivated forms with purple, silver, or variegated leaves are highly prized.

  • Traditional medicine
  • Crafts

Bonus Tip

Excellent for low-maintenance gardens.

For an extra boost, consider applying a thin layer of high-quality organic mulch around the base of the plant. This helps retain soil moisture, suppresses weeds, and gradually improves soil structure as it breaks down. This simple step can make a significant difference in the plant's overall vigor and resilience, especially during periods of extreme weather.

Plant Conservation

Conservation Status

Pittosporum tenuifolium , also known as kōhūhū or black matipo, is a small evergreen tree endemic and widespread throughout New Zealand, its native range. It is found in coastal to montane shrubland and forested habitats, preferring successional habitats.The NZPCN lists its current conservation status as "Endemic and widespread throughout country," indicating that it is not currently considered threatened in its native habitat.While it is native to New Zealand, Pittosporum tenuifolium has naturalized in other regions, including Victoria, Tasmania, and New South Wales in Australia, and California in the United States. In some of these areas, it is considered an invasive species.