Coin-Leaved Tree Daisy
Olearia nummularifolia
This native plant, known as Coin-Leaved Tree Daisy (scientific name: Olearia nummularifolia ), 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 .
Plant Description
Identification and Physical Characteristics
The coin‑like leaves of Olearia nummularifolia make it a distinctive shrub of subalpine ledges and open scrub Discover more about native shrubs. Although direct rongoā is limited in records, its role as hardy shelter and late‑season nectar aligns with māra kai and restoration values. Community projects use eco‑sourced plants to knit together rocky slopes above treelines, where its compact whorls reduce wind scouring and provide seasonal resources for ngā manu and pollinating insects.Coin-leaved Tree Daisy ( Olearia nummularifolia ), also known as Coastal Daisy or Round-leaved Olearia, is an evergreen shrub native to the South Island of New Zealand. It typically grows to about 3 to 6 feet (approximately 1 to 2 meters) tall and wide, with a dense, bushy, and much-branched habit. It features rounded, thick, leathery, and often silvery-green or yellow-green leaves that are evergreen, with a soft, slightly fuzzy texture. The leaves are small, typically 5-10mm long and 4-6mm wide, and are sometimes described as coin-shaped. The underside of the leaves may have a brownish tomentum, and the edges are often rolled under. In spring and summer, it produces small, delicate white daisy-like flowers, which appear at the branch tips and attract native pollinators such as bees and beneficial insects. Its stiff branches can give it an unusual, box-like appearance.
Quick Facts
| Scientific Name | Olearia nummularifolia |
|---|---|
| Height | 2-6 m |
| Spread | 2-4 m |
| Water Needs | Low to moderate |
| Light | Full sun to partial shade |
| Frost Tolerance | Moderate to good |
| Salt Tolerance | Moderate |
| Growth Rate | Moderate |
| Lifespan | Long-lived |
Climate Best Suited to
Olearia nummularifolia is well adapted to various New Zealand regions.
Regional Suitability
| City | Climate Suitability |
|---|---|
| Auckland | High |
| Wellington | High |
| Christchurch | Medium |
Plant Habitat
Natural Occurrence and Ecology
Coin-leaved Tree Daisy is native to New Zealand, typically inhabiting alpine and subalpine regions, thriving in dry, open environments and low scrub at elevations usually ranging from 600 to 1,400 meters. In the southern parts of New Zealand, it can also be found at lower altitudes. This species is notably resilient to drought, cold, and exposure, a characteristic attributed to its harsh subalpine habitat.
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 Olearia nummularifolia 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 Coin-Leaved Tree Daisy
Cultivating Olearia nummularifolia ( Olearia nummularifolia ) 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 Olearia Nummularifolia 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.
- Collect seeds
- 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.
- Take cuttings
- Use rooting hormone
Additional Methods
Depending on the growth habit of Olearia nummularifolia , 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.
- Divide clumps
- 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
Round-leaved tree daisy plays a visible role in coastal identity plantings and wildlife-friendly gardens; its compact, coin-leaved form and spring flowers support pollinators while celebrating local coastal flora. Olearia nummularifolia , also known as Coastal Daisy or Round-leaved Olearia, is a native evergreen shrub from New Zealand. Its "cultural value" primarily refers to its ecological and horticultural importance rather than deep traditional or symbolic cultural significance. Ecologically, Olearia nummularifolia provides nectar and shelter for native insects and birds, making it important in coastal ecosystems and beneficial for wildlife gardens that support pollinators. It is also used in native plant and restoration projects. Horticulturally, it is valued for its distinctive round, silvery-green leaves and delicate white daisy-like flowers that appear in spring and summer. Its compact, bushy, and rounded habit, along with its resilience to drought, cold, and exposure, makes it suitable for coastal gardens, low-maintenance landscapes, mixed shrub borders, and informal hedging and screening. The species name "nummularifolia" itself refers to its coin-shaped leaves. No specific traditional uses by indigenous people, symbolic meanings, or historical importance are widely documented beyond its ecological and landscaping benefits.
- 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
Olearia nummularifolia , also known as the coin-leaved daisy bush or hard-leaved tree daisy, is currently classified as "Not Threatened" in its conservation status. This classification has been consistent since at least 2004, with reviews in 2009, 2012, and 2017 reaffirming this status. This evergreen shrub is native to New Zealand and is found in subalpine areas, typically at elevations between 600 and 1,400 meters. It is known for its resilience to drought, cold, and exposure, making it suitable for various landscaping purposes, including coastal gardens and low-maintenance landscapes. While other species within the Olearia genus, such asOlearia adenocarpa, are critically endangered, Olearia nummularifolia itself does not face significant conservation concerns.