Large-Fruited Coprosma

Coprosma macrocarpa

Not Threatened

This native plant, known as Large-Fruited Coprosma (scientific name: Coprosma macrocarpa), 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 Shrubs.

Large-Fruited Coprosma (Coprosma macrocarpa) showing its large glossy leaves — Image credit: Large-Fruited Coprosma (*Coprosma macrocarpa*) - photo by Wikipedia contributors, via Wikipedia

Plant Description

Coprosma macrocarpa, also known as the Large-Fruited Coprosma or Coastal Karamū, is a robust and visually striking shrub or small tree endemic to New Zealand. Typically growing up to 6 metres in height, it is most celebrated for its exceptionally large, bright orange or red berries, which are the largest produced by any member of the Coprosma genus in the country. The foliage is equally impressive, consisting of large, thick, and highly glossy dark green leaves that are broadly oval in shape. These leaves feature prominent midribs and visible veins, with small pits called domatia located on the undersides. In spring, the plant produces small, inconspicuous green flowers. As a dioecious species, individual plants are either male or female, meaning both are required in proximity for the female plants to produce their iconic fruit.

Quick Facts

*Coprosma macrocarpa* quick facts
Scientific Name	Coprosma macrocarpa
Height	Up to 6 metres
Spread	2-3 metres
Water Needs	Moderate
Light	Full sun to partial shade
Frost Tolerance	Hardy
Salt Tolerance	High
Growth Rate	Moderate to Fast
Lifespan	30-60 years

Climate Best Suited to

Large-Fruited Coprosma is ideally suited to coastal and lowland temperate climates. It is primarily found in the North Island and offshore islands, where it benefits from the high humidity and moderated temperatures of the sea air. It is very tolerant of salt-laden winds.

Regional Suitability

City suitability for Large-Fruited Coprosma
City	Climate Suitability
Auckland	Excellent
Whangārei	Excellent
Tauranga	Very Good
Gisborne	Very Good
Wellington	Good (in sheltered coastal spots)

Plant Habitat

This species is primarily a coastal dweller, with its distribution focused on the northern half of the North Island and various offshore islands, including the Three Kings Islands. It is well-adapted to the challenges of coastal environments, demonstrating remarkable tolerance to salt spray and strong winds. Large-Fruited Coprosma is commonly found clinging to damp, shaded coastal cliffs, growing within coastal forests, or forming part of the dense scrubland that buffers the shoreline. While it prefers the humidity and moderate temperatures of coastal zones, it can also be found in lowland forest environments further inland, where it continues to provide essential food and shelter for native wildlife.

Growing Requirements

Soil Requirements

Thrives in well-draining soils but is adaptable to various conditions.

Free-draining loam
Enriched sandy soils
Coastal cliff soils

Light Requirements

Performs best in bright light but can handle significant shade.

Full sun (promotes density)
Partial shade
Dappled light

Water Requirements

Requires moderate, consistent moisture during its first year.

Weekly watering when young
Drought tolerant once established
Benefit from coastal humidity

Planting and Establishing

When planting Coprosma macrocarpa, choose a location that can accommodate its eventual height and spread. It makes an excellent hedge or specimen plant in coastal gardens. Dig a hole twice the width of the root ball and mix in plenty of compost. Ensure the plant is set at the same depth as it was in the nursery pot. Water deeply immediately after planting. Applying a generous layer of mulch around the base will help retain soil moisture and keep the roots cool, which is especially important in more exposed sunny positions.

Ecological Role

Large-Fruited Coprosma is a key species for supporting native fauna. Its exceptionally large berries are a major food source for native birds, particularly kererū, which are capable of swallowing the large drupes and dispersing the seeds over wide areas. Native lizards also feed on the fallen fruit. The plant's dense habit provides critical nesting habitat and shelter for small birds and a safe refuge for native insects and invertebrates, contributing significantly to the health of coastal ecosystems.

Uses & Significance

Garden Uses

A fantastic choice for gardeners seeking a structural, wildlife-friendly native.

Coastal windbreaks and screens
Feature plant with attractive fruit
Hedges in coastal environments
Attracting birds and lizards to the garden

Ecological Value

Provides essential ecosystem services, particularly in northern coastal areas.

Primary food source for kererū
Habitat for coastal lizard species
Important for coastal forest restoration

Landscaping Uses

In landscaping, Coprosma macrocarpa is highly valued for its lush, glossy green foliage which provides a permanent, high-quality look. Its ability to withstand salt spray makes it indispensable for beach-front properties. It can be used as a dense, fast-growing hedge or as a backbone plant in a large native shrubbery. The bright berries provide a splash of seasonal colour that is hard to beat. It also works well when used in restoration projects to stabilize coastal banks and provide quick canopy cover.

Seasonal Care Calendar

Spring

Apply fertilizer and monitor for new growth and flower development.

Apply organic fertilizer
Refresh mulch layers
Plant new specimens

Summer

Ensure adequate hydration and enjoy the ripening of the large drupes.

Regular deep watering
Monitor for bird and lizard activity
Tip-prune if needed for shape

Autumn

A great time for propagation and preparing the plant for the cooler months.

Take semi-hardwood cuttings
Collect fresh seeds
Reduce watering as temperatures drop

Winter

Perform structural pruning and maintain general garden hygiene.

Prune for size and density
Clean up any debris around base

When to Prune and How Much

Large-Fruited Coprosma responds very well to pruning, which can be used to maintain its shape or create a dense hedge.

Prune in late winter or early spring
Remove any frost-damaged tips
Hard-pruning is tolerated to rejuvenate old specimens

Use clean, sharp tools to make clean cuts. For hedges, regular light trimming will produce a much denser and more attractive result than occasional heavy pruning.

How to Grow Large-Fruited Coprosma

Cultivating Large-Fruited Coprosma (Coprosma macrocarpa) is an excellent way to introduce a touch of the New Zealand coast into your garden. Its hardy nature, attractive glossy foliage, and spectacular berries make it a standout choice for coastal landscaping, restoration projects, or as a structural element in a larger garden. Cultivating this species allows you to appreciate the subtle beauty of New Zealand's understory plants up close.

From Seed

Seeds should be collected from fully ripe drupes. Fresh seed has the highest success rate.

To sow from seed:

Soak drupes in water to remove the pulp.
Sow cleaned seeds into a tray of seed-raising mix.
Lightly cover with soil and keep moist.
Store in a warm, bright position out of direct sun.
A short period of cold stratification can improve germination.

Seedlings can be moved to individual pots once they have several sets of leaves. Allow them to grow for at least a year before planting out.

From Cuttings

Semi-hardwood cuttings are a reliable way to propagate Coprosma macrocarpa, especially if you want to ensure the sex of the new plant.

Take cuttings in late summer or early autumn:

Select 10-15cm healthy stem tips.
Remove leaves from the bottom two-thirds.
Use rooting hormone for better results.
Place in a well-draining mix of peat and perlite.
Keep in a humid, warm environment until roots form.

Additional Methods

While seed and cuttings are the standard methods, layering can also be used for lower-growing branches. Pinned-down stems will often develop roots at the nodes if kept in contact with moist soil over a period of several months.

Once roots are established, the new plant can be severed and moved to its permanent location. This is a very reliable, though slower, method of propagation.

Pin a healthy branch to the ground.
Cover the node with soil and mulch.
Keep moist for several months.
Check for roots before detaching.

Pests & Diseases

Coprosma macrocarpa is generally very healthy. It can sometimes attract scale insects, mealybugs, or aphids, which can be managed with neem oil or insecticidal soap. Sooty mould may appear if scale infestations are heavy. Ensure good air circulation and avoid over-fertilizing with high-nitrogen products, as this can encourage soft growth that is more susceptible to pests.

Cultural Significance

The Coprosma genus has many traditional uses in Māori culture. While specific historical records for C. macrocarpa are less common than for larger species like C. robusta, the Coprosma berries were recognized as a food source for birds, which were in turn important for Māori. The plant's role in the healthy, functioning coastal forest ecosystem was inherently respected.

Source of food for birds, supporting traditional hunting
Hardy nature valued for coastal shelter
Part of the complex web of traditional coastal knowledge

Bonus Tip

If you want a truly spectacular berry display, plant at least three Large-Fruited Coprosmas in a group. This increases the chances of having both male and female plants, ensuring a prolific crop of those iconic red fruits every year.

Plant Conservation

Currently classified as "Not Threatened," Coprosma macrocarpa remains common across its northern coastal range. However, habitat loss due to coastal development and modification remains an ongoing concern. Promoting its use in coastal restoration and urban garden settings helps ensure its long-term survival and maintains the vital links in northern coastal ecological corridors.