Gibbs' Bulbinella
Bulbinella gibbsii
Alpine lily for well‑drained, sunny sites; plant in gritty soils with good air circulation and avoid winter wet. See more in alpine plants .
Plant Description
Botanical Features
Bulbinella gibbsii, commonly known as Gibbs' Onion or the Stewart Island Lily, is a fleshy-rooted herbaceous perennial endemic to Stewart Island. It features strap-like, fleshy green leaves arranged in a tuft, resembling a vegetable onion but unrelated. In summer (January-February), it produces striking, dense racemes of star-shaped bright yellow flowers held on stout stalks above the foliage. There are two varieties: var. gibbsii, which is larger and found in damp bogs from coast to alpine, and var. balanifera, a smaller alpine specialist.
Quick Facts
| Light | Full sun |
|---|---|
| Soil | Lean, gritty, free‑draining |
| Water | Low to moderate; dislikes winter wet |
| Scientific Name | Bulbinella gibbsii |
| Height | Variable by habitat |
| Spread | Forms clumps or patches |
| Water Needs | Low to moderate; free-draining soils |
| Frost Tolerance | High - tolerant of severe freezes |
| Salt Tolerance | Low to moderate |
| Growth Rate | Slow to moderate |
| Lifespan | Long-lived perennial |
Bulbinella gibbsii is an alpine lily naturally suited to the cool, moist, and often boggy climates of Stewart Island, particularly thriving in areas with consistent rainfall and high humidity. It is adapted to conditions with mild summers, cool winters, and regular exposure to cold, moist air, reflecting its subantarctic origins.
| City | Climate Suitability |
|---|---|
| Whangārei | Suitable |
| Auckland | Suitable |
| Hamilton | Suitable |
| Tauranga | Suitable |
| Rotorua | Suitable |
| Gisborne | Suitable |
| New Plymouth | Suitable |
| Napier | Suitable |
| Whanganui | Suitable |
| Palmerston North | Suitable |
| Wellington | Suitable |
| Nelson | Suitable |
| Christchurch | Suitable |
| Dunedin | Suitable |
| Invercargill | Suitable |
Natural Habitat
Stewart Island Endemic
This species is restricted to Stewart Island (Rakiura). Var. gibbsii inhabits damp, peaty ground, cushion bogs, seepages, and the margins of pools from sea level up to the subalpine zone. It thrives in cold, constantly wet soils. Var. balanifera is found in higher alpine tussock grasslands, herbfields, and on talus slopes where drainage is sharper but conditions remain cool and moist. It is a characteristic plant of the island's unique bog vegetation.
Conservation Status
Bulbinella gibbsii is currently classified as "Not Threatened" under New Zealand's threat classification system, reflecting stable populations across its restricted Stewart Island distribution. While generally secure, local populations can be vulnerable to habitat degradation from drainage changes in bog ecosystems and the impact of introduced herbivores. Conservation efforts focus on protecting its unique bog and alpine habitats from disturbance and maintaining the ecological integrity of Stewart Island.
How to Grow
Cultivation Requirements
Bulbinella gibbsii is a specialist alpine lily that thrives in cool, moist, and well-aerated conditions, making it challenging to grow outside of its natural southern New Zealand habitats. It requires consistently moist, acidic, humus-rich soil, similar to bog or peaty environments, and good air circulation. Ensure a sunny to lightly shaded position and protect from winter wetness around the crown.
Planting Guide
Cultivation
Bulbinella gibbsii is challenging to grow outside of cool, southern climates. It requires permanently moist, peaty, acidic soil that never dries out. Plant in full sun to light shade. It is ideally suited for a bog garden, the edge of a pond, or a seep in a cool climate garden. It resents root disturbance, so choose its final position carefully.
Ecological Role
Bog Ecosystems
As a dominant herb in Stewart Island's bog communities, it provides seasonal nectar for native insects during its summer flowering. Its fleshy root system helps store energy to survive the harsh, nutrient-poor conditions of peat soils. The plant dies down in winter, retreating to its rootstock to survive the cold.
Uses
Garden Value
Primarily grown by specialist collectors and enthusiasts of subantarctic flora. Its bright yellow floral display is spectacular in mass plantings in a damp meadow or bog garden. It provides a unique architectural form with its thick, succulent leaves.
Landscaping Uses
Garden Design Applications
Excellent for rock gardens, alpine collections, and naturalistic plantings. Best used in open, well-drained positions where its distinctive form can be appreciated. Combines well with other native alpine plants and provides year-round structure. Consider placement carefully due to sharp foliage - avoid high-traffic areas. Creates dramatic focal points in contemporary and native-themed garden designs.
Seasonal Care
Year-Round Maintenance
Spring management focuses on removing winter-damaged foliage and assessing drainage. Summer care emphasizes maintaining adequate moisture without waterlogging. Autumn preparation includes reducing irrigation and ensuring good air circulation. Winter protection may require covering in areas subject to excessive moisture. Year-round monitoring ensures early detection of problems and maintenance of optimal growing conditions.
Pruning
Maintenance
Pruning is restricted to tidying up. Once the foliage dies back in late autumn or winter, the withered leaves can be gently removed to keep the area tidy. Leave flower heads to set seed if propagation is desired, otherwise remove spent stalks to tidy the clump.
How to Grow Gibbs' Bulbinella
From Seed
Propagation from fresh seed is the best method for Bulbinella gibbsii. Collect seeds immediately upon ripening in autumn from the capsules. Sow the fresh seeds onto a moist, peaty seed mix, barely covering them. Maintain cool temperatures and consistent moisture (avoiding waterlogging) throughout the germination period. Germination can be erratic, so patience is required. Once seedlings are large enough to handle, carefully prick them out and grow them on in individual pots in a cool, sheltered, and bright location. Given its specific habitat requirements, replicating these conditions for seedlings is crucial for success.
From Division
Division of established clumps is possible in early spring just as new growth commences, but it must be done with extreme care. The fleshy roots of Bulbinella gibbsii are brittle and easily damaged, which can significantly set the plant back or even lead to its demise. If dividing, gently lift the clump and carefully separate sections, ensuring each piece has a healthy portion of roots and foliage. Replant immediately into prepared soil, minimizing root disturbance. Water thoroughly after replanting and keep consistently moist until the divisions are well-established. Due to the sensitivity of its root system, division is generally not the preferred method unless absolutely necessary.
General Cultivation
Gibbs' Bulbinella is an alpine lily that requires specialized growing conditions to thrive, often challenging outside of cool, southern climates. It needs a sunny to lightly shaded location (full sun is tolerated if soil remains moist) with permanently moist, peaty, acidic soil that never dries out. Incorporate peat moss or acidic compost into the planting area and maintain soil pH between 4.5-6.0. Good air circulation is vital, especially given its boggy natural habitat, to prevent fungal issues. It is ideally suited for a bog garden, the edge of a pond, or a seep in a cool climate garden. Avoid root disturbance once established, so choose its final position carefully. Water regularly during dry periods, ensuring consistent moisture without waterlogging. This species dislikes winter wetness around the crown, so ensure excellent drainage. Protect from slugs and snails that can damage succulent young foliage in spring.
Pests and Diseases
Common Issues
Slugs and snails can be voracious feeders on the succulent young foliage in spring. Aphids may attack the flower spikes. In warmer, humid climates, the plant is susceptible to fungal rots and collar rot if drainage is poor or the soil becomes stagnant.
Cultural Significance
Local Identity
The plant is named after H.J. Gibbs, an early collector on Stewart Island. It is an iconic biological symbol of Rakiura (Stewart Island), representing the distinct evolutionary path of flora isolated on New Zealand's third main island.
Bonus Tip
Climate Indicator
This plant is a true cool-climate indicator. If you struggle to grow hostas or astilbes because it is too dry or hot, Bulbinella gibbsii will likely fail. It demands the cool, moist air and soil of the "Roaring Forties" latitudes.
