Silver Dollar Gum Tree
Latin Name: Eucalyptus polyanthemos
Price range: $16.95 through $38.95
- Hardiness Zone: Zone 8, Zone 9, Zone 10, Zone 11
- Pot Size: 4 Inch, 1 Gallon, 5 Gallon (Local Pickup Only)
Eucalyptus polyanthemos is an evergreen tree from southeastern Australia, sold in the United States as silver dollar gum. Young plants carry round, coin-shaped leaves covered in a pale waxy bloom, and that coin shape is where the common name comes from. As the tree ages, the leaves stretch into longer gray-green ovals held in a rounded, open crown. The waxy coating is a dry-climate adaptation. It reflects sunlight and slows water loss on the stony slopes where the species grows in the wild. Trunks often lean or bend rather than rising straight, which gives older trees an uneven, weathered outline.
Plant Details
Quick Information
- Latin Name: Eucalyptus polyanthemos
- Plant Family: Myrtaceae
- Common Names: Silver Dollar Gum, Red Box, Redbox Gum
- Origin / Native Range: Wooded foothills and tablelands of New South Wales, the Australian Capital Territory, and Victoria, southeastern Australia
- Mature Height × Width: 30–60 ft × 20–40 ft
- Exposure Requirements: Full Sun
- Irrigation Requirements: Low
- USDA Hardiness Zones: 9–11
- Cold Hardiness: 15°F–20°F
- Bloom Time: Late Winter through Summer, varying by region
- Bloom Color: Creamy White
General Information
The change in leaf shape is the easiest way to follow this tree’s development. Seedlings and young shoots hold nearly circular leaves in opposite pairs along the stem. Adult growth is longer and narrower, and the leaves hang singly rather than in pairs. Bark tells a similar story: young trunks are smooth and mottled in gray and cream. With age, the lower trunk builds up rough, short-fibered brown bark that flakes away in patches, while the upper limbs stay smooth and shed in strips. Flowers open in clusters near the branch tips. They have no showy petals. What you see instead is a dense puff of creamy white stamens, the thread-like male parts that carry pollen. Small woody capsules follow, each holding seeds finer than dust.
In the wild, this species grows on stony and gravelly slopes between roughly 400 and 2,500 feet in elevation. Those sites drain quickly and dry out between rains, and that history shapes how the tree behaves in gardens. Established plants get by on infrequent deep watering, but they resent heavy soils kept constantly wet. In warm inland areas, trees planted in wet clay often develop pale, yellowing leaves. Fast-draining ground and full sun give much better results. The heavy bloom draws large numbers of honey bees, and eucalyptus honey is a recognized product of these trees. In a landscape, silver dollar gum works as a shade tree, a windbreak, or a screen, though it needs room. Young trees also tend to grow crooked, so many growers stake and train them for the first few years.
The names are worth knowing. Eucalyptus comes from Greek words meaning “well covered”, a reference to the cap that seals each flower bud until it opens. The species name polyanthemos means “many-flowered”. Bloom timing shifts with climate. Trees in mild coastal and desert areas of the American Southwest often flower in the cooler months, while others bloom from spring into summer. The round juvenile leaves are cut and sold widely for floral work, and gardeners can encourage that stage by pruning young plants hard. Two limits deserve mention. The species has escaped cultivation in parts of coastal California, so check local guidance before planting near open space. Trunk-boring beetles can also damage stressed trees, which is another reason to match this plant to a dry, sunny, well-drained site. Eucalyptus foliage contains strong aromatic oils that are not safe to eat.
General Planting & Cultivation Information
Even drought-tolerant plants require regular watering until they are well established, good drainage is essential. If planting in containers, avoid pots without drainage holes.
Irrigate by watering deeply and then allowing the top several inches of soil to dry between waterings. This encourages the plant to send roots deep into the earth in search of moisture, helping it to become established, prevent root rot, build drought tolerance, and resilience to wind, heat, and cold.
The length of time between waterings will vary depending on your growing conditions and environment. Use a moisture meter for precise irrigation.
When planting, set the plant at the same depth as it was in its current container. For trees, ensure the top of the root flare is at soil level.
Young plants are vulnerable to harsh conditions, so consider growing them in larger containers until mature.
When planting in the ground, research the optimal planting season for your climate zone and protect young plants from frost.
To support establishment, consider creating a microclimate with nurse plants, shade, or wind protection. This can reduce stress, conserve soil moisture, and increase long-term success.
Protect the small, immature plants from rabbits and deer.
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