| Botanic name | Eucalyptus cinerea |
| Other names | Silver dollar eucalyptus, silver dollar gum, Argyle apple |
| Main Origin | Southeastern Australia |
| Mature size | 8 – 10 m x 10 – 15 m (w x h) |
| Mature form | Upright with a broad, spreading canopy |
| Foliage | Round, elliptical, heart- or spear-shaped |
| Growth rate | Fast |
| Position | Full sun |
| Soil | Adapts to most soils |
| Water | Regular deep watering during extended dry periods |
| Climate | Mediterranean, temperate, subtropical |
| Flower | Cream-white in spring and summer |
| Use | Specimen tree, shrub, hedging, screening, windbreak |
| Notes | Cold-tolerant |
IN THIS ARTICLE
Origin and distribution
Eucalyptus cinerea, commonly known as the Silver Dollar Eucalyptus or Argyle apple, is a striking evergreen tree prized for its distinctive, eye-catching silvery blue leaves.
Native to southeastern Australia, this species occurs in open forests, dry woodlands, and rocky hillsides, often on shallow, infertile soils, with a scattered distribution in elevated regions primarily within the southern part of the Great Dividing Range.
Widely cultivated in cooler regions due to its cold tolerance, it has become naturalised in Canberra, Australia and perhaps other parts of the world.
Growth and care
In its native habitat, Eucalyptus cinerea enjoys a temperate to subtropical climate, although it adapts well to the Mediterranean climate in cultivation. These climates tend to have cool to mild winters and warm to hot summers, with moderate rainfall and low to moderate humidity.
Once established, Eucalyptus cinerea is highly tolerant of drought. Mature trees are considered frost-hardy and can tolerate cold temperatures to -10°C. Young trees are susceptible to frost damage.
While somewhat cold-tolerant, this species cannot endure prolonged freezing conditions like Eucalyptus gunnii, an alpine species also renowned for its juvenile foliage.
Eucalyptus cinerea is well-suited to various soil types, like sandy, rocky, loamy or clay soils. While it can tolerate temporary wet conditions, the tree cannot endure prolonged waterlogging. Heavy clay soils should be amended with organic matter like compost, coarse grit or gypsum.
Applying a layer of mulch around the tree base can help retain moisture and suppress weeds. This species is highly adaptable to nutrient-poor soils, additional fertilisation is often unnecessary.
For container planting, however, the light application of a balanced slow-release fertiliser during the growing season can benefit foliage development.
As a large specimen tree, Eucalyptus cinerea does not require extensive maintenance. Removing dead, broken, or overgrown branches and surface trimming to maintain a tidy appearance is sufficient.
However, this plant responds well to pruning, which allows for shaping it into various forms, like a shrub or a small tree. Pruning a young tree hard to its base (coppicing) can result in multi-stemmed growth for a bush, informal hedge or screen.
If a small tree is desired, consider pollarding (cutting the tree at a higher point), followed by regular pruning to maintain an attractive bushy, compact form and rounded juvenile foliage.
Features
Eucalyptus cinerea is a fast-growing, medium-sized tree with a broad, rounded, pyramidal or irregular-shaped canopy. A mature tree can reach 10 – 15 metres tall with an 8 – 10 metre spread.
Its bark is rough, fibrous, fissured or stringy, grey or reddish brown, and often persists on the trunk and larger branches without shedding completely in ribbons.
Younger trees often develop long branches that spread outwards, resulting in a slightly weeping or cascading effect. Mature trees have more upright, less arching branches derived from thick, sturdy trunks.
The highlight of Eucalyptus cinerea is its fascinating silvery-blue, rounded, elliptical, or heart-shaped juvenile leaves persisting through the tree’s life. These leaves are developed in opposite pairs, equally spaced along each stem, creating a visual spectacle.
The foliage of younger trees is often densely clustered, giving the canopy a full and lush appearance, while older trees appear more open and airy.
The aesthetic appeal of its foliage makes this plant highly popular in the cut-flower industry. The silvery-blue colour gives a modern and elegant look, while its cool tones work well with bright flower colours in floral arrangements.
Its flowers are creamy-white to pale yellow, often in clusters of three, emerging from spring to summer, although exact timing can vary with the climate and region. Small conical-shaped woody fruits follow.
Uses
- Ornamental feature: Its magnificent foliage and tree form are perfect for a focal point or accent plant. The textured bark adds year-round visual appeal.
- Contrast planting: The silvery-blue tone and glaucous covering offer great contrast in the background while highlighting other ornamentals.
- Hedging and screening: They can be planted in a row and maintained as a hedge or privacy screen.
- Windbreak: Its strong and upright form makes it an excellent windbreak in windy areas.
- Urban planting: The species tolerates compacted and poor soils, making it highly suitable for urban sites.
- Floral design: The striking juvenile foliage is widely used among florists.
- Pot planting: Maintain its size by regular pruning. This species can be kept small in a sizable container on a patio or balcony.
- Water-wise gardening: Its high drought tolerance and adaptability to various soils make it suitable for dry landscaping.
FAQs
What is the Eucalyptus cinerea growth rate?
Eucalyptus cinerea has a moderate to fast growth rate of 1 – 1.5 metres annually. The growth rate depends largely on climate, soil, watering, and pruning.
Can you keep Eucalyptus cinerea small?
Yes. You can keep Eucalyptus cinerea small through proper pruning every early spring and maintenance techniques:
- Coppicing: Cut the tree back to about 15 – 30 cm above the ground to encourage a multi-stemmed shrub form and maintain its juvenile foliage development.
- Pollarding: Cut back the top growth annually to encourage multiple short branches. This method is ideal if a small tree form is desired.
- Pot cultivation: Growing it in a large container naturally restricts root expansion, helping to keep the plant smaller.
- Frequent trimming: Focus on removing long and leggy branches and trim regularly to maintain its compactness.
Does Eucalyptus cinerea have invasive roots?
The Silver Dollar Eucalyptus does not have highly invasive roots, although its roots can expand extensively, which may require careful consideration when planting.
The root system is typically shallow and spreading, mirroring its canopy’s dripline or slightly beyond. In compact soils, the roots may grow closer to the surface, potentially causing lifting or cracking of pavements.
Potential issues: If planted too close to buildings, sidewalks, or driveways, the roots can cause minor damage over time. In dry conditions, moisture-seeking roots may interfere with pipes or drainage systems.
Best practices: Plant at least 4 – 6 metres away from structures and underground utilities. If planting a tall specimen tree, envision its root expansion (canopy spread) and choose the planting site carefully.
