<i>Corynocarpus laevigatus</i>(Corynocarpus laevigatus) hero image

Karaka

Corynocarpus laevigatus

Not specified

This native plant, known as Karaka (scientific name: Corynocarpus laevigatus ), 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>Corynocarpus laevigatus</i>(Corynocarpus laevigatus) showing <i>Corynocarpus laevigatus</i>growth habit
Image credit: Karaka ( Corynocarpus laevigatus ) - Photo via Wikipedia

Plant Description

Identification and Physical Characteristics

Corynocarpus laevigatus , commonly known as Karaka or New Zealand laurel, is a medium-sized evergreen tree endemic to New Zealand Discover more about native ferns. It typically grows to heights of 15-20 meters, with a stout trunk that can reach up to 60 centimeters in diameter. The bark is generally grey. Its leaves are distinctive: leathery, dark to bright green, glossy, and typically 15-30 cm long, with an elliptic to obovate-oblong shape. From August to November, the tree produces small, greenish-yellow flowers in erect panicles. These are followed by large, oval-shaped, orange fruits, about 30-40 mm in length, which ripen from December to February. Each fruit contains a single, poisonous seed. The tree is mostly found in coastal areas, though it can also grow inland in the North Island of New Zealand, and on the Chatham Islands, Kermadec Islands, and Three Kings Islands.

Quick Facts

Corynocarpus laevigatus quick facts
Scientific Name Corynocarpus laevigatus
Height 10-15 m
Spread 8-12 m
Water Needs Moderate
Light Full sun to part shade
Frost Tolerance Poor to moderate
Salt Tolerance Good
Growth Rate Moderate
Lifespan Very long

Climate Best Suited to

Corynocarpus laevigatus is well adapted to various New Zealand regions.

Regional Suitability

City suitability for Corynocarpus laevigatus
City Climate Suitability
Auckland High
Wellington High
Christchurch Medium

Plant Habitat

Natural Occurrence and Ecology

Karaka ( Corynocarpus laevigatus ) is a prominent medium-sized evergreen tree endemic to New Zealand, primarily inhabiting coastal and lowland forests. Its natural distribution is concentrated in the northern half of the North Island, extending southwards to coastal areas of the lower North Island and specific locations in the South Island, such as Banks Peninsula and Okarito. It is also a significant component of the flora on the Chatham Islands, Kermadec Islands, and Three Kings Islands. Karaka thrives in temperate conditions, preferring full sun and moist, well-drained, fertile soils. While highly tolerant of coastal conditions and salt spray, its relative intolerance to frost, especially when young, limits its inland presence in colder regions. Historically, its distribution has been influenced by Māori plantings, making its exact indigenous range somewhat uncertain, but its adaptability has led to its naturalization in lowland forests beyond its original boundaries.

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 Corynocarpus laevigatus 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 Karaka

Cultivating Corynocarpus laevigatus ( Corynocarpus laevigatus ) 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 Corynocarpus laevigatus 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 Corynocarpus laevigatus , 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

Corynocarpus laevigatus , known as karaka by Māori and k pi by Moriori, holds significant cultural and historical importance for both indigenous peoples of New Zealand. It is considered a taonga (cultural treasure).Food Source:Primarily, karaka was a vital food source. The flesh of the fruit was consumed, and the kernels, though containing a lethal neurotoxin called karakin, were highly prized after careful preparation to remove the toxin. This preparation was an important cultural practice, and the prepared kernels could be eaten fresh, stored, or ground into flour.Māori Mythology:In Māori mythology, C. laevigatus is believed to have originated from Hawaiki, the ancestral homeland of the Māori people.Traditional Medicine (Rongoā Māori):Māori used the leaves of the karaka tree for medicinal purposes. The undersides of the leaves were used to draw out infections, while the fresh upper surfaces were applied to heal injured skin.Moriori Dendroglyphs (Rākau Momori):On the Chatham Islands, Moriori people carved depictions of their ancestors onto karaka trees, known as rākau momori. These carvings are considered internationally significant and unique to Moriori culture.Spiritual Significance:The tree also held powerful spiritual significance, with stories arising about its journey from Hawaiki.Widespread Planting:The exact indigenous distribution of karaka is uncertain due to its widespread historic planting by Māori, who cultivated it across the country for its food value. It is often found in association with Māori cultural deposits and can be seen planted in straight lines, circles, or groves in areas of former Māori occupation.Despite its cultural value, karaka is also viewed as an environmental weed outside its natural range, as it can outcompete native vegetation and disrupt local ecosystems. The management of karaka presents a challenge in balancing its cultural significance with ecological integrity.

  • 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

Corynocarpus laevigatus , commonly known as karaka or New Zealand laurel, is classified as "Not Threatened" under the New Zealand Threat Classification System (NZTCS). The IUCN Red List of Threatened Plants Status indicates that this taxon has not yet been assessed. It is considered abundant in its native range.However, it is naturalized and considered an invasive species in Hawaii.