Acacias for Adelaide Gardens
from S.G.A.P Journal, November 1983, 9(1)
The combination of limestone and clay in soils of many parts of Adelaide has created problems in the cultivation of numerous species of Australian plants.
It is not surprising that once a species has been successfully grown it tends to become rather ubiquitous. Hence species like Acacia saligna, Acacia iteaphylla, Acacia podalyriifolia, Melaleuca armillaris, Westringia fruticosa and the dreaded Grevillea rosmarinifolia can be found, it sometimes seems, in almost every Adelaide native garden.
The following acacias are not so widely cultivated but have been successfully grown in clay-limestone soils and I recommend them for Adelaide gardens.
Acacia beckleri (Barrier Range Wattle). An erect, open, yet compact species, it grows to about 2 m in height and is very spectacular in flower. The globular flower heads are dense, deep yellow and profuse, and among the largest of the genus (their diameter may be 25 mm!) The buds are purplish, and attractive for a long time before flowering commences in winter.
Acacia fimbriata (Fringed Wattle). This graceful species is extremely fast growing, and in winter is covered in masses of lemon yellow, fragrant flowerheads, It grows to about 6 metres, and is a very hardy species which will grow in full sun or part shade.
Acacia glaucoptera (Clay Bush Wattle) is a small spreading shrub growing to less than 1 m in height. This species has most unusual and ornamental foliage, and makes an excellent feature plant for either a semi-shaded site or a position in full sun. The golden yellow globular flowerheads appear in early spring.
Acacia glandulicarpa (Hairy-pod Wattle) is another low (to about 1.5 m) spreading ornamental species which can be used as a ground cover. The flowers are globular and golden yellow, and completely cover the plant from late winter to spring. A. glandulicarpa can be grown in a hot sunny position or in part shade.
Acacia pentadenia (Karri Wattle). A tall shrub to about 3 m in height, this species has very ornamental foliage. The bipinnate leaves are almost fern-like in appearance, and their dark green contrasts well with the pale yellow, fragrant globular flower heads (flowering mainly in spring). It will accept severe pruning, and makes an excellent screen plant.
Acacia lineata (Streaked Wattle) grows to about 1 m in height but may spread to 3 or 4 m which makes this species a useful taller ground cover. The foliage is neat, and if the plant becomes too spreading or straggly it can be safely pruned. It is very attractive in flower, with masses of deep yellow to orange yellow small globular flower heads (late winter, spring).