Grevillea robusta (Silky Oak)
Silky Oak, Silk Oak, Silky-Bark Oak
Fast-growing and stately, Grevillea robusta (Silky Oak) is an evergreen tree of great beauty. Pyramidal when young, it develops a few horizontal limbs when older, giving it a broader top. Mature specimens produce a striking display of large, rich, bright golden orange flowers, up to 5 in. long (12 cm), in dense, one-sided spikes in spring-summer. Equally attractive is the foliage of olive-green, fern-like leaves, to 12 in. in length (30 cm), silvery underneath. Frost hardy to 16°F (-8°C), although it becomes semi-deciduous under those conditions, Silky Oak is often grown as an annual for the beauty of its foliage.
- Recipient of the prestigious Award of Garden Merit of the Royal Horticultural Society
- Grows up to 75 ft. tall (22 m).
- Easily grown in acidic, well-drained soils in full sun. Drought tolerant once established. Use little to no phosphorus fertilizer.
- Deer resistant
- Great as a specimen plant in Mediterranean gardens and xeriscape gardens.
- Virtually disease free and pest free.
- Propagate by seed, semi-hardwood cuttings or graft.
- Native to Australia
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Requirements
Hardiness | 10
– 12 |
---|---|
Heat Zones | 3
– 12 |
Climate Zones | 8, 9, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, H1, H2 |
Plant Type | Trees |
Plant Family | Grevillea |
Exposure | Full Sun |
Season of Interest |
Spring (Early,Mid,Late) Summer (Early,Mid,Late) |
Height | 70' (21m) |
Water Needs | Low |
Maintenance | Low |
Soil Type | Loam, Sand |
Soil pH | Acid, Neutral |
Soil Drainage | Moist but Well-Drained, Well-Drained |
Characteristics | Plant of Merit, Showy, Evergreen |
Native Plants | Australia |
Tolerance | Deer, Drought |
Attracts | Birds, Butterflies, Hummingbirds |
Garden Styles | Mediterranean Garden |
(c) Gerhard Bock, SucculentsandMore.com
While every effort has been made to describe these plants accurately, please keep in mind that height, bloom time, and color may differ in various climates. The description of these plants has been written based on numerous outside resources.
Requirements
Hardiness | 10
– 12 |
---|---|
Heat Zones | 3
– 12 |
Climate Zones | 8, 9, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, H1, H2 |
Plant Type | Trees |
Plant Family | Grevillea |
Exposure | Full Sun |
Season of Interest |
Spring (Early,Mid,Late) Summer (Early,Mid,Late) |
Height | 70' (21m) |
Water Needs | Low |
Maintenance | Low |
Soil Type | Loam, Sand |
Soil pH | Acid, Neutral |
Soil Drainage | Moist but Well-Drained, Well-Drained |
Characteristics | Plant of Merit, Showy, Evergreen |
Native Plants | Australia |
Tolerance | Deer, Drought |
Attracts | Birds, Butterflies, Hummingbirds |
Garden Styles | Mediterranean Garden |