Overview
Grevillea wickhamii, commonly known as Wickham's Grevillea or Holly-Leaf Grevillea, is a striking species of flowering plant in the family Proteaceae. First described by Carl Meissner in 1856, this endemic Australian plant has captivated botanists and gardeners alike with its unique features and adaptability.
Summary
Grevillea wickhamii is widespread across northern Australia, thriving in Western Australia, the Northern Territory, and western Queensland. It's an erect shrub or spindly tree, growing 1–6 metres tall. The plant's distinctive holly-like leaves and vibrant flowers make it a standout in its native habitats and gardens alike.
Key Features
The plant boasts broadly egg-shaped leaves, 30–90 mm long and 25–55 mm wide, with 2-7 shallow, pointed teeth near the tip. Its flowers are arranged in down-curved, sometimes branched clusters. Flower colours vary by subspecies, including cream, yellow, red, orange, and deep pink, adding to its ornamental appeal.
Natural Habitat
Grevillea wickhamii thrives in arid regions of northern Australia. It's well-adapted to harsh conditions, making it drought-tolerant and low-maintenance. The plant's natural distribution spans diverse landscapes, from sandy plains to rocky outcrops, demonstrating its resilience and ability to flourish in challenging environments.
Growing Guide
Grevillea wickhamii, a resilient Australian native, thrives in specific conditions. Follow these guidelines to successfully grow and maintain this striking shrub in your garden.
Requirements
Grevillea wickhamii demands full sun exposure and well-drained, rocky or sandy soil. It's a rounded shrub reaching up to 4 metres in height. Plant in areas with hot overhead sun, sheltered from strong winds. This species adapts well to warmer, drier climates, mirroring its native habitat in Northern Territory and northern Western Australia.
Planting Tips
Choose a spot with excellent drainage to prevent root rot. Consider raised garden beds or elevated mounds with free-draining soil. Water thoroughly for the first six months after planting. Follow up with twice-weekly watering for 2-3 weeks, then reduce to once weekly for about four weeks. This regimen helps establish strong roots.
Maintenance
After establishment, Grevillea wickhamii requires minimal maintenance. It's drought-tolerant, needing little water once established. Prune lightly after flowering to maintain shape and promote bushiness. Watch for signs of overwatering or poor drainage, which can lead to root problems. Avoid fertilisers high in phosphorus, as they can damage the plant.
Uses & Benefits
Grevillea wickhamii offers numerous benefits for gardeners and wildlife alike. Its versatility and unique features make it a valuable addition to various landscapes and ecosystems.
Garden Design
Grevillea wickhamii's growth habit makes it an excellent choice for diverse garden designs. As an erect shrub or spindly tree reaching 1–6 m in height, it's perfect for creating visual interest. Use it as a focal point, windbreak, or screen in your garden. Its adaptability allows for creative placement in both formal and informal settings.
Wildlife Benefits
The nectar-rich flowers of Grevillea wickhamii attract a variety of wildlife. Birds, especially honeyeaters, and native bees frequently visit the blooms. This makes it an ideal plant for creating a wildlife-friendly garden. By incorporating G. wickhamii, you're providing a valuable food source for local fauna, contributing to biodiversity in your area.
Special Features
Grevillea wickhamii boasts distinctive holly-like leaves and vibrant flowers, making it a standout ornamental plant. Its drought tolerance and low maintenance requirements are additional special features. Traditionally, Aboriginal peoples used grevillea flowers for their sweet nectar, either consuming it directly or mixing it with water to create a refreshing drink.
Problems & Solutions
Grevillea wickhamii, while hardy, can face certain challenges in cultivation. Here's a guide to common issues, care tips, and seasonal considerations to ensure your Holly-leaf Grevillea thrives.
Common Issues
Grevillea wickhamii is sensitive to poor drainage and overwatering, which can lead to root rot. It's susceptible to phosphorus toxicity, so avoid high-phosphorus fertilisers. Watch for common garden pests like aphids, whiteflies, and spider mites. In areas with high humidity or poor air circulation, fungal diseases may occur. Protect young plants from strong winds to prevent damage.
Care Tips
Plant Grevillea wickhamii in full sun and well-drained soil. Water thoroughly for the first six months, then reduce frequency. Prune lightly after flowering to maintain shape and promote bushiness. Use low-phosphorus, native plant fertilisers sparingly. Mulch around the base to retain moisture and suppress weeds. Monitor for pests regularly and treat promptly if detected. Ensure good air circulation to prevent fungal issues.
Seasonal Notes
In spring, expect vibrant flowering and increased growth. Summer brings peak bloom; water deeply but infrequently during dry spells. Autumn is ideal for planting and light pruning. In winter, reduce watering as the plant becomes dormant. Protect from frost in colder regions. Year-round, maintain good drainage and avoid overwatering. Adjust care based on your local climate to ensure optimal health and flowering.
Additional Information
Grevillea wickhamii offers a variety of subspecies and cultivars, each with unique characteristics. Here's some additional information to help you explore this fascinating plant further.
Varieties
Grevillea wickhamii has six recognised subspecies:
- G. wickhamii subsp. aprica: Red or orange flowers, blooming most months with a peak from May to August.
- G. wickhamii subsp. cratista: Red to deep pink flowers, blooming in July.
- G. wickhamii subsp. hispidula: Yellow or bright red flowers, blooming from May to August.
- G. wickhamii subsp. macrodonta, pallida, and wickhamii: Each with distinct characteristics.
Where to Buy
You can purchase Grevillea wickhamii from:
- Specialised native plant nurseries
- Online Australian plant retailers
- Local garden centres in arid regions
- Botanic gardens' plant sales
Native plant societies' annual sales events
Check availability as it may vary seasonally and by location.Australian Native Plants Society (Australia): Comprehensive species profiles
- Flora of Australia online: Detailed botanical descriptions
- State herbarium websites: Distribution maps and identification guides
- Australian National Botanic Gardens: Cultivation advice
- Local native plant nurseries: Specific growing tips for your area