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

Colenso's Pittosporum

Pittosporum colensoi

Not specified

This native plant, known as Colenso's Pittosporum(scientific name: Pittosporum colensoi ), 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 colensoi</i>(Pittosporum colensoi) showing <i>Pittosporum colensoi</i>growth habit
Image credit: Colenso's Pittosporum ( Pittosporum colensoi ) - Photo via Wikipedia

Plant Description

Identification and Physical Characteristics

Pittosporum colensoi ( Pittosporum colensoi ) is a small, evergreen tree or shrub native to New Zealand Discover more aboutNew Zealand. It is characterized by its flat, leathery, oval leaves, which are typically 4-10 cm long and 2-5 cm wide, and paler on the underside. The foliage can develop from a bright green to a mature deep purple. This plant produces dark purple, star-shaped flowers. These are often described as small, fragrant, and bell-shaped, appearing in masses through summer. Following the flowers, it develops hard, spherical, woody capsules about 12mm wide that split into three to reveal black seeds embedded in a sticky pith. It is a resilient plant that thrives in well-drained soils, tolerates coastal winds, and can grow in partial shade. It can reach a height of up to 5 meters and a width of 3 meters, with a medium growth rate.

Quick Facts

Pittosporum colensoi quick facts
Scientific Name Pittosporum colensoi
Height 3-6 m
Spread 2-4 m
Water Needs Moderate
Light Partial shade to full sun
Frost Tolerance Good
Salt Tolerance Poor
Growth Rate Moderate
Lifespan Long-lived

Climate Best Suited to

Pittosporum colensoi is well adapted to various New Zealand regions.

Regional Suitability

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

Plant Habitat

Natural Occurrence and Ecology

Pittosporum colensoi ( Pittosporum colensoi ), also known as Rautāwhiri, is a small, evergreen tree or shrub endemic to New Zealand. It is typically found in forest margins and lowland to montane forests, often in successional habitats, across both the North and South Islands, up to an altitude of 3,500 feet (approximately 1,067 meters).Well-Drained Soils:This resilient plant thrives in well-drained soils, indicating its preference for sites where water does not accumulate.Coastal Tolerance:It can tolerate coastal winds, making it suitable for areas near the coast, though it is not explicitly stated to be salt-tolerant.Light Conditions:It prefers partial shade but can also grow in full sun, showcasing its adaptability to varying light levels within its natural environment.Widespread:Its distribution across both the North and South Islands highlights its adaptability to a range of climatic conditions within New Zealand.Forest Margins and Lowland to Montane Forests:It is a common component of these forest types, often found in areas where there is some disturbance or transition, such as the edges of forests or regenerating areas.The presence of Pittosporum colensoi in these diverse habitats underscores its ecological flexibility and its role in contributing to the biodiversity 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 colensoi 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 Colenso's Pittosporum

Cultivating Pittosporum colensoi ( Pittosporum colensoi ) 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 colensoi 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 colensoi , 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

While Pittosporum colensoi is a native New Zealand shrub or small tree, readily found in its natural habitat and cultivated for ornamental purposes, there is no widely documented specific cultural significance or traditional Māori uses directly attributed to this particular species in the available information.The plant is named after William Colenso, a notable Cornish missionary, printer, botanist, explorer, and politician in New Zealand. While other Pittosporum species, such as Tarata (P. eugenioides) and Kāro (P. crassifolium), were valued by Māori for their fragrance and used in scents or body lotions, similar specific uses for Pittosporum colensoi are not explicitly documented in primary references.

  • 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 colensoi is currently classified as "Not Threatened" according to the 2017 conservation status assessment by the NZPCN. This status has been consistent in previous assessments from 2004, 2009, and 2012 as well. It is an endemic vascular plant to New Zealand.