Divaricating Kōhūhū
Pittosporum divaricatum
Pittosporum divaricatum , commonly known as the Divaricating Kōhūhū, is a highly architectural and resilient evergreen shrub endemic to New Zealand. It is a classic example of New Zealand's unique "divaricating" flora, characterized by a dense, tangled network of stiff, interlacing branches that grow at wide angles. This habit evolved as a defense against browsing moa and provides a fascinating misty or cloud-like texture in the landscape. Found across the lower North Island and eastern South Island, it is a tough survivor of forest margins and scrublands. In spring, it produces small, solitary, dark red flowers that are almost black, followed by woody capsules that attract forest birds. Its rugged elegance and adaptability make it an exceptional choice for modern native gardens, rockeries, and low-maintenance structural plantings.
Plant Description
Divaricating Kōhūhū typically grows as a dense, rounded shrub reaching a mature height of 2 to 3 meters. Its growth form is its most striking feature: slender, flexible branchlets that branch repeatedly at wide angles to form an impenetrable, tangled mass. The plant exhibits heteroblasty, meaning the leaves change significantly as it matures. Juvenile leaves are often lobed or toothed (pinnatifid), while adult leaves are small (5-12 mm long), leathery, and can be either entire or deeply notched.
In spring, the shrub produces small, solitary flowers at the branch tips. These are dark reddish-purple to nearly black and are about 5-8 mm long. While individually small, they are quite striking against the greyish-white stems. The flowers are followed by woody, egg-shaped capsules that split into two or three valves to reveal sticky black seeds embedded in an orange pith. These seeds are a high-energy food source for native birds such as the Tūī and Silvereye.
Quick Facts
Plant Specifications
| Scientific Name | Pittosporum divaricatum |
|---|---|
| Family | Pittosporaceae |
| Height | 2.0-3.0 metres |
| Growth Form | Dense, interlaced divaricating shrub |
| Foliage | Small, leathery leaves (variable juvenile/adult) |
| Flowers | Solitary, dark red to black; Spring |
| Light | Full sun to partial shade |
| Soil | Well-drained loam or stony soil |
| Hardiness | Very hardy; tolerates frost, wind, and drought |
| Water Needs | Low to moderate once established |
| Spread | 1.5-2.5 metres |
| Frost Tolerance | Very High (Hardy to -8°C or lower) |
| Salt Tolerance | Moderate to High |
| Growth Rate | Medium |
| Lifespan | Perennial (Long-lived) |
Climate Best Suited to
Divaricating Kōhūhū is a hardy species suited to a wide range of New Zealand climates. It is particularly well-adapted to the cooler, drier climates of the eastern South Island and the lower North Island. It thrives in high-light environments and handles severe winter frosts and cold, drying winds with ease. It is less successful in the very humid, subtropical districts of the far north where the air movement is low.
Regional Suitability
| Whangārei | Suitable (requires breezy site) |
| Auckland | Suitable |
| Hamilton | Suitable |
| Rotorua | Ideal |
| Tauranga | Suitable |
| Gisborne | Ideal |
| New Plymouth | Ideal |
| Whanganui | Ideal |
| Palmerston North | Ideal |
| Napier | Ideal |
| Wellington | Ideal |
| Nelson | Ideal |
| Christchurch | Ideal |
| Dunedin | Ideal |
| Invercargill | Ideal |
| City | Climate Suitability |
|---|
Plant Habitat
Naturally, Pittosporum divaricatum is an inhabitant of the forest edge and scrubland. Its range extends from the Volcanic Plateau and southern North Island through to the eastern side of the main divide in the South Island. It is commonly found in lowland to montane forests, particularly at forest margins where light levels are higher. Its preferred habitats include rocky slopes, river terraces, and subalpine scrub communities. It is often a key member of the "grey scrub" association, growing alongside other tough divaricating plants like Coprosma propinqua and Aristotelia fruticosa .
Plant Conservation
Divaricating Kōhūhū is currently classified as "Not Threatened." It remains widespread and locally common across its natural range. However, like many dryland and forest-margin shrubs, it faces ongoing pressure from habitat loss due to land conversion and competition from invasive weeds such as gorse and old man's beard. Regeneration can also be hampered by browsing from introduced mammals like cattle and goats. It is a valued species for ecological restoration projects, particularly those focused on re-establishing the complex structure of New Zealand's traditional "grey scrub."
Growing Requirements
Soil Requirements
Adaptable to most soil types but demands good drainage. It thrives in well-drained loams, stony or gravelly soils, and can handle slightly acidic to neutral pH levels.
- Well-drained loam or sand
- Tolerates poor soil fertility
- Dislikes heavy, waterlogged clay
Light Requirements
Grows best in full sun, which maintains its tight, architectural form and encourages the most prolific flowering. It can handle partial shade but may become more open and less structural.
- Full sun for best density
- Tolerates partial shade
- Open, exposed positions
Water Requirements
Requires consistent moisture while establishing its root system (the first 1-2 years). Once mature, it is remarkably drought-tolerant and handles dry summer spells with ease.
- Moderate watering when young
- Highly drought tolerant once established
- Avoid over-watering in Winter
Planting Guide
Best Planting Practices
Plant in autumn or spring. Choose a sunny, well-drained spot with good air movement. Dig a hole twice the width of the container. If the soil is naturally heavy, incorporate some coarse sand or grit to improve drainage. Plant at the same depth as the nursery container and water in thoroughly. Apply a thin layer of organic mulch around the base to suppress weeds, but ensure it is kept away from the main stem to prevent rot. This species is very tough and will usually establish quickly without needing much intervention.
Ecological Role
Environmental Benefits
Divaricating Kōhūhū is a powerhouse for biodiversity. Its dense, tangled branches provide an impenetrable refuge and safe nesting habitat for small native birds. The dark flowers are a nectar source for insects, and the sticky seeds are highly sought-after by honey-eaters and fruit-eating birds. Crucially, the plant's structural form provides an ideal microhabitat for native skinks and geckos, who seek refuge within the network of branches.
Uses & Significance
Garden Uses
A versatile and structural shrub for various garden styles:
- Sculptural feature in rock or scree gardens
- Tough informal hedge or screening plant
- Excellent for low-maintenance, modern minimalist designs
- Lizard-friendly habitat planting
Ecological Value
Provides essential refuge and food resources for native birds and reptiles.
Cultural Significance
Traditional Uses and Values
The name Kōhūhū connects this plant to the wider family of Pittosporums, which were highly valued by Māori for their aromatic resins and medicinal properties. While specific traditional uses for this species are less recorded than for its larger relatives, the divaricating habit was recognized for its resilience. Today, it is valued as a taonga of the forest edge and dryland remnants, representing the unique evolutionary history of New Zealand's island flora.
Landscaping Uses
Garden Design Applications
In landscape design, Pittosporum divaricatum is used for its incredible geometric texture. It creates a misty, cloud-like effect that provides a soft but permanent structure in the garden. It is a fantastic choice for modern native designs where it can be used as a stand-alone focal point or mass-planted to create an undulating groundcover. Its neutral grey-green colour pairs beautifully with bold architectural plants like Phormium (Flax) or dark-leaved shrubs. It is also an excellent plant for dry, windswept banks where other species fail.
Seasonal Care
Spring
Apply a general-purpose native fertilizer; watch for the small dark red flowers.
Summer
Water young plants during dry spells; enjoy the structural haze of branches.
Autumn
Optimal time for planting; collect seed capsules as they split to reveal black seeds.
Winter
Fully hardy to frost; enjoy the clean geometric branch structure.
Pruning
Pruning Techniques
This species requires very little actual pruning. Its naturally compact and slow-growing form is part of its charm. If it becomes too large or encroaches on a path, it can be lightly trimmed with shears in late summer. It responds very well to light clipping if a more formal, rounded shape is desired. Avoid hard pruning into old, non-leafy wood, as it can be slow to recover from heavy cuts. Always use sharp, sterilized tools.
How to Grow Divaricating Kōhūhū
From Seed
Propagation from seed is the standard and most successful method. Collect the seed capsules when they start to split. Remove the sticky black seeds and wash them in water. Sow them on a tray of quality seed-raising mix and cover with a very thin layer of grit or sieved mix. Place in a cool, bright spot. Germination can be slow and may take several months. Seedlings should be kept in a sheltered spot until they are well-established before planting out.
From Cuttings
Cuttings can be challenging but are possible. Take semi-hardwood cuttings in late summer. Select healthy, firm stems about 10 cm long. Dip the base in a rooting hormone and plant in a free-draining mix of 70% perlite and 30% peat. Maintain high humidity and provide bottom heat if possible. Success is variable, so taking multiple cuttings is recommended.
Troubleshooting Common Issues
The primary cause of failure is root rot from poor drainage. Ensure the site is free-draining. Like other members of the genus, it may occasionally host scale insects, which can be managed with horticultural oil if the infestation is severe. Rabbit and hare browsing is the primary threat to young plants - ensure they are protected with a wire guard until the stems are tough and woody.
Pests & Diseases
Generally very healthy and pest-resistant. It is much less prone to the "pittosporum psyllid" that affects many of the larger-leaved garden cultivars. Occasionally targeted by scale or aphids on new growth, but these are easily managed.
Bonus Tip
Divaricating Kōhūhū is perfect for "cloud pruning." By lightly trimming the outer edges of the shrub once a year, you can emphasize its soft, mounded shape, making it look like a piece of living sculpture in a modern or Japanese-inspired garden.
