Forest Cabbage Tree
Cordyline banksii
Cordyline banksii, also known as the forest cabbage tree or by its Māori name tī ngahere, is a monocot tree endemic to New Zealand. This palm-like small forest tree can grow up to 4 meters (13 ft) tall, with some sources stating up to 12 feet. It typically has multiple erect branches, though it can also be single-stemmed or branch close to the ground to form a dense clump. native trees
Plant Description
Its distinctive leaves are long (1-2 meters or 6-7 feet), narrow (4-8 cm or 1.6-3.1 inches wide), and lanceolate, often described as "paddle-shaped" and drooping. A prominent, flat midrib runs the entire length of the leaf. The leaves taper into a long, channeled leaf stalk that widens again to enclose the stem. In summer, Cordyline banksii produces large panicles (1-2 meters long) of sweetly perfumed white flowers. These are followed by small, globe-shaped fruits, 4-5 mm in diameter, which can be white, bluish-white, or blue.
Quick Facts
| Scientific Name | Cordyline banksii |
|---|---|
| Height | Up to 4m |
| Spread | Up to 2m |
| Water Needs | Medium |
| Light | Full sun to part shade |
| Frost Tolerance | Hardy to -5°C |
| Salt Tolerance | Moderate |
| Growth Rate | Moderate |
| Lifespan | Long |
Climate Best Suited to
Cordyline banksii is common in coastal, lowland, and lower montane forests throughout the North Island of New Zealand. In the South Island, it is widespread in the northern half and extends down the west coast to about Haast. It can also occasionally be found in subalpine habitats in the South Island. This species is often found in shrublands, where it may hybridize with Cordyline pumilio. It tolerates a wide range of situations, including open woodlands, forest margins, scrubland, rocky banks, and hillsides with scrubby secondary growth, up to an elevation of about 1000m.
Regional Suitability
| City | Climate Suitability |
|---|---|
| Whangārei | Ideal |
| Auckland | Ideal |
| Hamilton | Ideal |
| Tauranga | Ideal |
| Rotorua | Ideal |
| Gisborne | Ideal |
| New Plymouth | Ideal |
| Napier | Ideal |
| Whanganui | Ideal |
| Palmerston North | Ideal |
| Wellington | Ideal |
| Nelson | Ideal |
| Christchurch | Ideal |
| Dunedin | Ideal |
| Invercargill | Ideal |
Plant Habitat
Cordyline banksii is common in coastal, lowland, and lower montane forests throughout the North Island of New Zealand. In the South Island, it is widespread in the northern half and extends down the west coast to about Haast. It can also occasionally be found in subalpine habitats in the South Island. This species is often found in shrublands, where it may hybridize with Cordyline pumilio. It tolerates a wide range of situations, including open woodlands, forest margins, scrubland, rocky banks, and hillsides with scrubby secondary growth, up to an elevation of about 1000m.
Plant Conservation
Cordyline banksii is classified as "Not Threatened" in New Zealand. Unlike Cordyline australis, it appears to be resistant to "sudden decline," a disease caused by the pathogen *Phytoplasma australiense*.
Growing Requirements
Soil Requirements
It thrives in rich, well-drained soils. It can adapt to a variety of soil conditions, including steep slopes and poorly drained sites.
- Rich, well-drained soils
- Adaptable to various soil conditions
Light Requirements
It prefers full sun but can tolerate part shade. For best color, multi-colored cultivars may prefer dappled light, while green-leafed plants do well in direct sun.
- Full sun to part shade
Water Requirements
It has medium water requirements and likes consistently moist soil, but not "wet feet" (standing water). Water regularly from spring to fall, and sparingly in winter, allowing the soil surface to dry between waterings.
- Consistently moist soil
- Water regularly in spring and fall
Planting Guide
Cordyline banksii is considered easy to grow and is valued for its ease of maintenance and adaptability. It can be easily grown from fresh seed, and cuttings from stems, trunks, and shoots root quickly. No pruning is typically required, but dead leaves below the crown can be removed.
Ecological Role
The sweetly perfumed flowers of Cordyline banksii attract native birds and insects, while the berries are a food source for birds.
Uses & Significance
Garden Uses
Cordyline banksii is useful for urban planting, border planting, and as a focal point in subtropical-themed gardens.
- Urban planting
- Border planting
- Subtropical-themed gardens
The Māori name for this plant is tī ngahere.
- Māori name: tī ngahere
Ecological Value
The flowers and fruit of Cordyline banksii provide a valuable food source for native birds and insects.
- Food source for native birds and insects
Landscaping Uses
In a landscaping context, Cordyline banksii is a versatile plant that can be used as a specimen tree, in mixed borders, or in containers. Its architectural form and attractive foliage make it a popular choice for a variety of garden styles.
Seasonal Care Calendar
Spring
In spring, new growth will appear. This is a good time to apply a slow-release fertilizer.
- Apply slow-release fertilizer
Summer
During summer, regular watering is beneficial, especially during dry spells. The plant will produce large panicles of sweetly perfumed white flowers.
- Water regularly
- Enjoy the flowers
Autumn
In autumn, the flowers will be followed by small, globe-shaped fruits.
- Look for fruit
Winter
In winter, the plant is largely dormant. Water sparingly, allowing the soil surface to dry between waterings.
- Water sparingly
When to Prune and How Much
No pruning is typically required, but dead leaves below the crown can be removed.
- Remove dead leaves as needed
Always use clean, sharp tools for pruning to minimize the risk of disease.
How to Grow Forest Cabbage Tree
From Seed
Cordyline banksii can be successfully propagated from fresh seed, offering excellent germination rates when proper collection and processing techniques are employed. The species produces small, white to pale blue berries that ripen during autumn and early winter months. Fresh seeds have significantly higher viability than stored seeds, making immediate processing crucial for optimal results. Berries are typically ready for collection when they feel soft and easily detach from the fruiting stalk with gentle pressure.
Collect ripe berries and remove the flesh completely by gently mashing in water, then floating away the pulp to leave clean, viable seeds. The seeds are relatively large compared to other native species, making processing easier. Rinse thoroughly and surface sterilize with diluted fungicide solution to prevent fungal diseases during germination. Sow immediately in a well-draining seed-raising mix containing equal parts quality potting mix, coarse sand, and perlite for optimal drainage and root development.
Maintain consistent soil moisture without waterlogging, keeping temperatures between 18-22°C for optimal germination conditions. Provide bright, indirect light and ensure good air circulation to prevent damping-off diseases. Germination typically occurs within 4-8 weeks but can occasionally extend to several months, particularly with older seeds. Once seedlings have developed their first sword-shaped leaves, transplant carefully to individual containers using a moisture-retentive but well-draining native plant potting mix. Young plants establish quickly and show vigorous growth when provided with consistent moisture and protection from extreme temperatures.
From Cuttings
Cordyline banksii is exceptionally easy to propagate from various types of cuttings, making it one of the most reliable native plants for vegetative propagation. The species readily produces adventitious roots from stem, trunk, and shoot cuttings, offering multiple propagation opportunities. This characteristic makes it valuable for restoration projects and landscape plantings where consistent results are essential.
Stem and trunk cuttings can be taken at almost any time of year, though summer months typically provide the fastest rooting response. Select healthy, mature stems of 15-30cm length, making clean cuts with sharp, sterile tools. Trunk sections can be even longer (30-60cm) and still root successfully, making this method ideal for creating instant mature-looking plants. Allow cut surfaces to dry for 24-48 hours in a shaded location to reduce disease risk and encourage callus formation.
Plant cuttings vertically in well-draining cutting mix, ensuring the correct orientation (top end up) for trunk sections. Insert approximately one-third of the cutting length into the growing medium, using a mixture of coarse sand, perlite, and quality potting mix for optimal drainage and nutrition. Maintain consistent moisture levels without waterlogging, and provide bright, indirect light in a warm position. Root development typically begins within 4-8 weeks, with new shoot growth appearing shortly afterward. Bottom heat can accelerate the rooting process, particularly during cooler months. Once established, young plants grow rapidly and can be transplanted to permanent positions within 6-12 months.
Pests & Diseases
Cordyline banksii is generally resistant to most pests and diseases. However, it can be susceptible to root rot in overly wet soils and occasionally to cordyline slime flux and honey fungus. Mealybugs can also be an issue, causing yellow and distorted leaves.
Cultural Significance
Known as tī ngahere, this forest cabbage tree sits within the wider tī group valued in te ao Māori. While Cordyline australis (tī kōuka) is the primary species referenced for kai and fibre, tī ngahere shares whakapapa within this rōpū. Tī species provided durable fibre and, in some rohe, starchy reserves baked for food; they also hold ongoing cultural presence in landscapes and marae plantings.
- Māori name: tī ngahere
- Part of the culturally significant tī group
- Associations with fibre and landscape planting traditions
Bonus Tip
Unlike the more common cabbage tree, Cordyline australis, Cordyline banksii appears to be resistant to the disease "sudden decline".
Related Plants
Explore other native trees that share similar characteristics or habitats with Cordyline banksii, offering further insights into New Zealand's diverse flora.