Grevillea rosmarinifolia

Grevillea rosmarinifolia, also known as Rosemary-leaved Grevillea, is a highly floriferous, evergreen bush, surprisingly hardy considering its origins. This particular botanical species is undoubtedly the one that has contributed the most to the discovery and appreciation of these fascinating Australian shrubs. It owes its species name to its small needle-like foliage, which resembles that of rosemary. It is appreciated for its long flowering period of bright red flowers, which sometimes starts in February and lasts for several months in mild climates. It is also valued for its dense habit, intense green foliage, and resistance to diseases and drought. Behind its green bushy appearance, this shrub hides a generous and undemanding nature: it definitely deserves a place in the garden. A small hole filled with sand and ericaceous soil should be dug for its root.

Grevillea rosmarinifolia is a bush from the proteaceae family, native to the cooler regions of southeastern Australia. Many Grevillea species are pioneers in their natural environment: they tolerate fairly poor, dry soils but do not appreciate the presence of limestone, and require full sun to flower. It grows rapidly, reaching maturity in 3-4 years, and has a rounded habit, occupying an average space of 2m (6 ft 7 in) in all directions. It develops thin ascending branches, forming a dense and somewhat bushy mass. Its small, narrow, and pointed leaves do not exceed 1.5 to 3cm (0.6 to 1.2 in) in length and are 1mm (0 in) wide. They are not smooth, hairy on the underside, and very vibrant green. The very decorative flower buds start forming in late autumn. The flowering truly explodes in February and lasts until May-June without interruption. In mild climates, it can bloom throughout the year if the soil remains slightly moist in summer. The bright raspberry red, flowers with pale yellow backs, are composed of petal-shaped styles coiled on themselves and long curved stamen, grouped in upright spider-shaped clusters. The root system of this plant is very dense on the surface, which allows it to adapt to nutrient-poor soils and summer drought.

Grevillea rosmarinifolia is one of the easiest species to grow, especially as it can withstand temperatures of -12 to -15°C (10.4 to 5 °F) in well-drained soil once well established. This bush requires little maintenance and can tolerate light pruning to keep it dense. It will easily thrive in coastal gardens in sheltered locations and preferably in light, filtering, and slightly acidic soil. Particularly suitable for Mediterranean climates, it can be combined with evergreen ceanothus to create opaque and flowering hedges for a very long period. It will also look good when planted alone on large slopes or at the back of dry garden beds, always in an open position and full sun. In an exotic or Mediterranean garden, it can be associated with proteas, Agave, Canary Island viper's bugloss, Euphorbia mellifera, Aloe aristata, Melianthus major, palms, Callistemon, and Leptospermum. Container cultivation allows for control over the substrate composition and enables the bush to be overwintered in a cold greenhouse or a very bright and minimally heated conservatory in very cold regions.