Grevillea robusta - Evergreen Trees Direct

Grevillea robusta - Silk Oak - Evergreen Trees Direct

Grevillea robusta - Silk Oak

$620.00

Tax included. Shipping calculated at checkout.

Size: 100L

100L 40cm/45L

Current Stock Height Guides

40cm/45L: 1.3m – 1.8m Approx.
100L: 2m – 2.4m Approx.

Height guide disclaimer: Height ranges are approximate only.

As living products, plant heights naturally vary between individual plants, batches, and seasons. No guarantee is given that supplied plants will fall within the stated range.

If minimum heights are required, you must confirm current batch heights with Evergreen Trees Direct prior to purchase.

Variation in height is normal and is not grounds for return, refund, replacement, or compensation.

All stock is grown, maintained and graded in strict accordance with AS 4373-2007, Australian Standard for Nursery Stock.

About Grevillea robusta - Silk Oak

Grevillea robusta, commonly known as Silk Oak or Australian Silver Oak, is a majestic evergreen native tree celebrated for its elegant form, fern-like pinnate foliage with silvery undersides, and vibrant orange-red flower clusters that bloom from late spring to early summer. Growing up to 30 meters tall and spreading 10–15 meters wide, this fast-growing tree creates bold scale and year-round structure in large gardens, parks, and open landscapes.

Thriving in full sun to partial shade and adaptable to various soils including clay and sand, Grevillea robusta is moderately drought-tolerant once established. Its upright, symmetrical shape with a conical crown makes it an excellent shade tree, ornamental feature, and habitat provider for native birds and pollinators. With low to moderate maintenance needs, Silk Oak is a reliable and striking choice for spacious outdoor settings that demand both beauty and ecological value.

Distinguishing Features

Grevillea robusta - Silk Oak is a great option for you if you:

Want Low Maintenance
Want Fast Growing
Want Your Tree To Grow Tall
Want Shade
Want To Avenue Plant
Want To Add Impact With A Feature Tree
Want A Flowering Tree
Want to Attract Birds And Bees
Want An Australian Native for Biodiversity
Want Something Easy to Manage

Mature Height & Width

Mature Height: 15m - 30m Approximately

Mature Width: 10 – 15 meters

Grevillea robusta - Silk Oak is expected to grow 40 – 60 cm per year (vigorous).

Root Ball Dimensions (Height & Width)

Use this as a reference when digging your planting hole. We recommend digging at least 10% wider than the dimensions below to encourage strong root development.

30cm Pot: 33cm (W) × 30cm (D)
40cm/45L Pot: 44cm (W) × 41.5cm (D)
50cm Pot / 70L Pot: 55cm (W) × 41.8cm (D)
100L Bag: 50.6cm (W) × 52.8cm (D)
150L Bag: 66cm (W) × 55cm (D)
200L Bag: 71.5cm (W) × 60.5cm (D)
300L Bag: 88cm (W) × 63.8cm (D)
400L Bag: 99cm (W) × 66cm (D)
500L Bag: 122cm (W) × 66cm (D)
750L Bag: 134cm (W) × 69cm (D)
1000L Bag: 146.3cm (W) × 71.5cm (D)
2000L Bag: 176cm (W) × 82.5cm (D)

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Shipping Cost

Shipping is calculated at checkout based on the pallet space your order occupies in the truck and your delivery location.

There is no charge to calculate your freight.

VOLUME DISCOUNTS

10% off orders over $1,000
15% off orders over $2,000
20% off orders over $7,500

Discounts Apply Automatically at Checkout

About Your New Grevillea robusta - Silk Oak

Grevillea robusta, commonly known as Silk Oak or Australian Silver Oak, is a majestic evergreen native tree celebrated for its elegant form, fern-like pinnate foliage with silvery undersides, and vibrant orange-red flower clusters that bloom from late spring to early summer. Growing up to 30 meters tall and spreading 10–15 meters wide, this fast-growing tree creates bold scale and year-round structure in large gardens, parks, and open landscapes.

Thriving in full sun to partial shade and adaptable to various soils including clay and sand, Grevillea robusta is moderately drought-tolerant once established. Its upright, symmetrical shape with a conical crown makes it an excellent shade tree, ornamental feature, and habitat provider for native birds and pollinators. With low to moderate maintenance needs, Silk Oak is a reliable and striking choice for spacious outdoor settings that demand both beauty and ecological value.

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Looks excellent when used in symmetrical rows or as stand-alone features in minimalist landscapes.

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Uses in my Garden

Feature Tree
Rural Property Planting
Shade Tree
Screening or Privacy

Grevillea robusta - Silk Oak works in an:

Australian Native Garden – celebrates local plants with natural character.
Tropical Garden – lush, leafy planting for a resort-style atmosphere.
Modern Garden – sleek, minimal, and design-led planting.
Low-maintenance Garden – resilient choices for easy care and year-round appeal.

Is Grevillea robusta - Silk Oak Evergreen or Deciduous?

Grevillea robusta - Silk Oak is an Evergreen (foliage year round) Tree

Mature Height & Width

Mature Height: 15m - 30m Approximately

Mature Width: 10 – 15 meters

Grevillea robusta - Silk Oak is expected to grow 40 – 60 cm per year (vigorous).

Growth Rate of Grevillea robusta - Silk Oak

Grevillea robusta - Silk Oak is expected to grow 40 – 60 cm per year (vigorous).

They are considered to have a:

Fast Growth Rate

Frost Tolerance & Ideal Climate to plant Grevillea robusta - Silk Oak

Is Grevillea robusta - Silk Oak frost tolerant?

Grevillea robusta - Silk Oak is Frost Hardy – Survives heavy and frequent frost without damage.

Does Grevillea robusta - Silk Oak Flower?

Grevillea robusta produces long, showy, golden-orange toothbrush-shaped flowers from late spring into early summer. These upright clusters sit above the fern-like foliage and create a striking seasonal display that stands out brilliantly against the tree’s deep green canopy.

Does Grevillea robusta - Silk Oak flower?

Yes - Flowers

Flowering Period:

Spring
Summer

Flower Type:

Fluffy

Flower Colour:

Yellow

Is Grevillea robusta - Silk Oak an Australian Native Tree?

Yes

Grevillea robusta - Silk Oak is Native to Native to eastern Australia, where it grows in subtropical and dry rainforests of Queensland and New South Wales.

What is the Wildlife Value of Grevillea robusta - Silk Oak ?

Its nectar-rich flowers attract honeyeaters, lorikeets, native bees and butterflies, making it a powerhouse for pollinators. The large evergreen canopy provides shelter and nesting habitat for birds, while the textured bark supports insects and microfauna that boost biodiversity in native and subtropical gardens.

How much Sunlight does Grevillea robusta - Silk Oak need?

Grevillea robusta - Silk Oak will thrive best in:

Full Sun
Part Shade

Preferred Soil?

Grevillea robusta performs best in well-drained sandy or loam soils and prefers slightly acidic to neutral conditions. It may struggle in heavy clay or poorly drained areas unless improved with organic matter and coarse material to enhance drainage. Keep soil evenly moist during establishment, then transition to deep, occasional watering as the tree matures to support its drought resilience, healthy structure and reliable flowering.

Is Grevillea robusta - Silk Oak Drought Tolerant?

Is Grevillea robusta - Silk Oak Drought tolerant?

As a young tree it requires regular watering, but once established the Silk Oak develops excellent drought tolerance. Naturally adapted to warm, dry and coastal conditions, it maintains vigorous growth and good canopy density with minimal supplementary watering.

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How To Plant Your Grevillea robusta - Silk Oak

How to Plant Grevillea robusta:

Select an Ideal Location: Choose a location with well-draining soil and sufficient space for this tree's eventual size.

Dig the Planting Hole: Dig a hole that's as deep and twice as wide as the root ball.

Position the Tree: Place the tree in the hole, ensuring the top of the root ball is level with the surrounding soil.

Backfill with Soil: Fill the hole with soil, gently tamping it down to remove air pockets.

Water Thoroughly: Provide a generous watering to help the tree settle in.

Recommended Planting Spacing For Your Grevillea robusta - Silk Oak

Feature Planting: Space 8 – 10 m apart for canopy development

Hedging & Screening: Not suitable

Avenue Planting: Space 10 – 12 m apart for full crown effect

Grevillea robusta - Silk Oak is expected to grow 40 – 60 cm per year (vigorous).

Fast Growth Rate

Long Term Care For Your Grevillea robusta - Silk Oak

Caring for Your Grevillea robusta:

Watering: During the first few years, maintain consistent soil moisture. Reduce watering frequency as the tree matures.

Pruning: Prune to maintain shape and remove dead or damaged branches. This tree typically requires minimal pruning.

Fertilization: Apply a balanced, slow-release fertilizer in spring to promote healthy growth.

Frequently Asked Questions

Frequently Asked Questions (FAQs):

Q: Can Grevillea robusta tolerate drought?
A: Yes, once established, Grevillea robusta is moderately drought-tolerant, making it suitable for regions with dry spells.

Q: What type of soil does it prefer?
A: Grevillea robusta can thrive in various soil types, including clay and sandy soils, as long as they are well-draining.

Q: Are the orange-red flowers attractive to wildlife?
A: Yes, the vibrant orange-red flowers of Grevillea robusta are known to attract birds and pollinators, adding to the tree's appeal in the garden.