Grevilleas Suited to a Mediterranean Type Climate
There are many varieties of grevilleas both 'natural' and hybrids. Natural species account for over 300 types with almost as many hybrids now available for home gardeners. Grevilleas are named after Charles Francis Greville, co-founder of the Royal Horticultural Society.
Grevilleas can be found to suit almost all climates and a great range of conditions. Western Australian has its share of native grevilleas, some of which are also popular for domestic gardens. California has a similar climate to Western Australia and grevilleas seem to be popular in the area.
In the south coastal heathlands of Western Australia, Grevillea tripartita (subspecies macrostylis) is endemic to the area and can be found in mallee or dense heath on in the East Mount Barren hills and near the coast. It is a variable shrub, growing between 1 to 2 metres in height and flowering over several months in spring and summer. This species was first described in 1856 by the Swiss botanist Carl Meissner.
On the coastal limestone areas of the coast and near-coastal areas, between Bunbury and Cervantes, can be seen the spider-net grevillea (G. preissii subspecies preissii). J A Ludwig Priess was a botanical collector and the species name commemorates his contribution. It is a low, spreading shrub to about a metre tall and flowers in winter and spring. It is quite common in gardens and several cultivars have been produced.
Several grevilleas are found through the jarrah forests from north-east of Perth almost to Albany on the south coast.
Wilson's grevillea (G.wilsonii) can be seen from spring to summer. It is also known as the native fuchsia. Although the flowers of this species may not be as abundant as some others, this prickly shrub is still very attractive. The brilliant red flowers blacken as they age. It grows to 1.5 metres in gravel areas throughout the region.
The catkin grevillea (G. synapheae subsp synapheae) prefers gravel soils but is also seen in sand. It is ideal as a ground cover and grows to 50cm. It has a long flowering period in spring and the foliage is very attractive. It is an ideal choice for south west gardens.
The fuchsia grevillea (G. bipinnatifida subsp bipinnatifida) – also known as the great grevillea is found in gravel and granite soils from Mogumber to Collie. It is ideal as a garden variety as it flowers almost the entire year round. It is a low-growing, sprawling shrub that grows to a metre high and has somewhat prickly leaves. The flower is similar to a wisteria raceme. It is one of the parents of G. Robyn Gordon, a very popular hybrid.
The rare pouched grevillea (G. saccata) is restricted to a few areas of sandy soil, mainly between Hill River and Dandaragan. It can be purchased by home gardeners and is an ideal candidate for a rockery. It is low-growing. Arching branches bear flowers from winter through spring.
Diels' grevillea (G. dielsiana) can be found growing on heathland and among low trees in sand inland between Mingenew and Kalbarri. This brilliant, upright to spreading flowering shrub bears its blossoms from autumn through to spring. The leaves are three part and deeply divided to the midvein. The leaf lobes are 8 to 20mm long and a millimetre wide. The margins of the leaf curve down over the lower surface of the leaf blade. It is very prickly but also very attractive for the home gardener with its red or apricot flowers. It ranges from 0.3 to 2 metres in height and has a spread of 1 to 2 metres. This variety attracts honeyeaters and the dense prickly foliage provides good protection for birds.
Wickham's grevillea (G. wickhamii subspecies aprica) is very widespread throughout the Gascoyne and Pilbara. It grows in woodland, shrubland, stony or gravely soil, sand, loam or clay from desert areas across to the coast. It may appear as a bushy shrub or as a slender tree to 5 metres tall. The flowering season is extended from autumn through winter and spring. The cream, yellow or red flowers are produced from April to October and intermittently at other times. The margins of the leaves are serrated and prickly. It is another variety that attracts birds.
In the Kimberley region in the far north of Western Australia, the silverleaf grevillea (G. refracta) grows to 6 metres in a variety of habitats. The flowers are carried in autumn through winter. The flowers may be golden yellow or red fading to yellow on the tips. The silver leaves are slender and the plant responds well to pruning. It is bird-attracting and is recommended as a water-wise plant for gardens north and inland of Perth.
Also found in the Kimberley (and across the north of Australia) but preferring sandy soils, often near watercourses is the fern-leafed grevillea (G. pteridifolia). This small tree can reach 10 metres and has greyish-green pine-like foliage and large racemes of orange flowers. It has a number of different forms and is the parent of a number of popular hybrids such as Honey Gem and Sandra Gordon. It flowers in winter and spring. The flowers are full of nectar and an important food source for small animals as well as birds.
Aborigines also take the nectar directly from the flowers or make a sweet drink by soaking the flowers in water. There is also a prostrate form to around 5 metres. Kakadu National Park has a silver-leaved type which grows to a small tree.
In the Goldfields region, often in arid-looking soils in woodlands, the Grevillea huegelii varies from an erect shrub to 2 metres of a low-spreading plant. South of Marvel Loch, a yellow form occurs together with the more widespread red. The main flowering season is late spring but they flower at other times, particularly after periods of rain. The stiff, leathery foliage is finely divided and an attractive bluish-green.
In the wheatbelt area, the bottlebrush grevillea (G. paradoxa) is one of the more unusual grevilleas. The flower spikes are held above the dense prickly foliage. The shrubs grow to 2 metres in sandheaths between Hyden and Mullewa. It is a low-growing looking shrub which makes a spectacular garden specimen. It loves sandy or gravely soils and is quick to flower in spring.
Generally, grevilleas like well-drained, even dry positions in (mostly) full sun. Western Australian grevilleas, in particular, are highly sensitive to fertilisers that provide phosphorous. In fact, they rarely need fertilising at all. Care should be taken when pruning grevilleas as some people react badly to the sap and may erupt in itchy welts and rashes which take some time to subside.
Keep an eye out for these lovely wildflowers when you're travelling. Suss them out in garden centres too so you can have your own beautiful grevilleas.