Grevillea robusta
silky oak
A fast-growing evergreen tree to 20m or more, but is usually grown as an annual for foliage effect making a bushy shrub to 3m. Olive-green, fern-like leaves to 30cm in length, paler beneath. Racemes of tubular yellow flowers are produced only by mature plants
Size
Ultimate height
Higher than 12 metresTime to ultimate height
20–50 yearsUltimate spread
4–8 metresGrowing conditions
Moisture
Moist but well–drained, Well–drainedpH
Acid, NeutralColour & scent
| Stem | Flower | Foliage | Fruit | |
| Spring | Yellow | Green | ||
|---|---|---|---|---|
| Summer | Yellow | Green | ||
| Autumn | Green | |||
| Winter | Green |
Position
- Full sun
Aspect
West–facing or South–facing
Exposure
Sheltered Hardiness
H2Botanical details
- Family
- Proteaceae
- Native to GB / Ireland
- No
- Foliage
- Evergreen
- Habit
- Bushy
- Potentially harmful
- Skin irritant/allergen. Wear gloves and other protective equipment when handling Pets: Skin irritant/allergen. For further information and contact numbers regarding pets, see the HTA guide to potentially harmful plants
- Genus
Grevillea can be evergreen shrubs or trees, with alternate, simple or pinnately divided leaves and petal-less flowers consisting of a colourful calyx tube with protruding style, borne in racemes or panicles
- Name status
Correct
- Plant range
- E Australia
How to grow
Cultivation
Grow outdoors in acid to neutral well-drained soil in a frost-free area or as part of a summer bedding scheme. Grow under glass in lime-free compost with added grit in full light. May need restrictive pruning under glass
Propagation
Propagate by seed, semi-hardwood cuttings or graft
Suggested planting locations and garden types
- Patio and container plants
Pruning
Pruning group 1 outdoors, but more rigorous pruning may be necessary indoors to restrict size
Pests
Generally pest-free
Diseases
May be susceptible to honey fungus (rarely)
Get involved
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