Silky oak
Grevillea robusta
A subtropical high-flyer that grows straight and fast, gives light shade and breaks wind without heavy cover. Frost-tender when young, so mind cold inland sites.
Silky oak in a syntropic line
Silky oak belongs in the Emergent layer as a Secondary species. They frame the line. Rough in-row spacing starts around 3.2 m in a syntropic row. Good line partners include Almond, Apricot. As a Secondary species it carries mid-term yield and structure while climax trees slowly claim the canopy.
Tolerances and growing conditions
- Strata
- Emergent
- Lifecycle
- Secondary
- Soil preference
- Sandy, Loam
- Soil pH range
- 5 – 7.5
- Min. temperature
- -4°C
- Min. rainfall
- 700 mm/year
- Wind tolerance
- Medium
- Frost tolerance
- Low
- Growth rate
- Fast
- Irrigation needed
- Low
- Foliage
- Evergreen
- Waterlogging tolerance
- Medium
- Origin
- Australia
- Native to Portugal
- No
How to manage it
Outstanding subtropical performer. Grows straight up for timber and windbreak, with light canopy and showy winter flowers.
How to propagate
Sow seed in warm conditions; grevillea is most reliably raised from seed.
Guidance, not a guarantee — success varies by species and skill.
What to watch out for
Regrows vigorously but is not a fast chop-and-drop biomass producer. Can suffer dieback in severe frost; needs winter protection in colder inland spots.
Frequently asked questions about Silky oak
Is silky oak frost-hardy?
Yes for winter cold in many climates — generally hardy to around -4°C when dormant, with low frost tolerance in the catalog. Flowering crops can still lose a season to late frost, so site them carefully.
What soil does silky oak need?
It does best on sandy, loam ground, at pH about 5–7.5.
How much water does silky oak need?
Plan for a rainfall floor around 700 mm/year, plus low irrigation once established.
Can silky oak handle wet or waterlogged soil?
It has medium waterlogging tolerance — short winter wet is usually fine, standing water is not.
What should I watch out for with silky oak?
Regrows vigorously but is not a fast chop-and-drop biomass producer. Can suffer dieback in severe frost; needs winter protection in colder inland spots.
Design your line to see how your land fits Silky oak.
Start designing your line →