Silky Oak
Grevillea robusta
Family: Proteaceae
What it is like
Bloom Color: Orange, Yellow. Main Bloom Time: Early spring, Late spring, Mid spring. Form: Oval, Pyramidal.
Grevillea robusta is an evergreen Tree growing to 30 m (98ft) by 15 m (49ft) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 9. It is in leaf all year, in flower from April to May. The species is hermaphrodite (has both male and female organs) and is pollinated by Bees. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid and neutral soils. It can grow in semi-shade (light woodland) or no shade. It prefers dry or moist soil and can tolerate drought.
Height (m): 30
Where it is found
Temperate rainforests
Australia - New South Wales, Queensland.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 2
The flowers are one of the richest sources of nectar. This can be sucked directly from the flowers, shaken into a bowl or washed out in a small quantity of water. The nectar falls in showers when the flowers are shaken.
Nectar: produced in such abundance by some flowers that it can be harvested fairly easily.
Gum: can be chewed as a chewing gum or can often be used as a sweetener or thickening agent in foods.
Medicine
Rating: 0
Other
Rating: 0
The plant yields small quantities of a gum resin. The leaves contain rutin, though quantities are not specified. Intense yellow and green dyes are obtained from the leaves. This tree is one of the most important reafforestation trees in Nepal. This species is more resistant than other members of the genus to root-rotting fungus, it is sometimes used as a rootstock for the more susceptible species. Wood - strong, silky textured, light, easily split, durable but porous. Used for panelling, joinery, cabinet making etc. A good fuel.
Dye: Plants that provide dyes.
Gum: Gums have a wide range of uses, especially as stabilizers, emulsifiers, thickening agents, adhesives etc.
Rootstock: Plants used as the rootstock for grafting scions onto.
Wood: A list of the trees and shrubs that are noted for having useful wood.
How it is grown
Landscape Uses:Container, Pest tolerant, Aggressive surface roots possible. An easy and fast-growing tree requiring a well-drained slightly acid soil and a sunny position. It prefers a rich moist soil, but it also succeeds in dry soils. Dislikes limey soils. Established plants are drought resistant. This species is not very hardy when grown outdoors in Britain. In its native range it does experience frosts, though these are normally light and short-lived. Plants tolerate temperatures down to -7°c in Australian gardens though this cannot be translated directly to British gardens because of our cooler summers and longer, colder and wetter winters. It is usually grown as a pot plant in Britain, though it rarely flowers here. A very ornamental plant, it is often grown as a street tree in suitable climates. Hybridizes freely with other members of this genus. The flowers are very attractive to bees. Plants in this genus are notably resistant to honey fungus. Special Features: Attractive foliage, Not North American native, Invasive, Naturalizing, Attractive flowers or blooms.
Propagating it: Seed - sow February in a warm greenhouse. Germination is usually good. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for at least their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts. Cuttings of half-ripe wood, 5 - 8cm with a heel, June/July in a frame.
Best place to grow: Woodland Garden Secondary; Sunny Edge; Dappled Shade;
Habit: Tree
Hardiness: 9-11
Growth: Fast
Soil: Light (sandy), medium, heavy (clay)
Shade: Semi-shade, no shade
Moisture: Dry, moist