Acacia longifolia

Acacia longifolia is commonly called Caterpillar Mimosa due to the appearance of its flowers clustered in fluffy spikes resembling bright yellow soft and harmless caterpillars. Its other name, Long-leaved Mimosa, refers to the large size of its leaves called phyllodes. It is a small tree or large bush with a wide crown, which flowers in late winter or early spring and retains its foliage all year round. Highly prized in coastal areas for stabilising sandy soils and blocking the wind, it will also thrive as a solitary plant, in a hedge or near a patio. This species is not demanding in terms of soil, resistant to salt spray and summer drought, but sensitive to cold. In cooler regions, it can be grown in a large container that can be overwintered in a bright, frost-free room.

Mimosas should not be confused with the tree we call acacia. They belong to the Fabaceae family, just like alfalfa and lupins. Acacia longifolia is native to the eastern part of Australia, where it can be found on the coast or along watercourses, in sandy or loamy soils. This highly competitive species is now considered invasive in the Var and Alpes-Maritimes regions, where it tends to spread along riverbanks, especially after repeated fires that promote seed germination. An adult specimen can withstand temperatures as low as -8°C (17.6°F). Once well-rooted, it tolerates dry and hot summers well.

This Long-leaved Mimosa develops a short trunk topped with a wider-than-tall, often irregular and very dense canopy. Its growth is fast, reaching around 4.5m (15ft) in height with a spread of 5.5m (18ft). Its bark is dark purple-grey, and its young branches are red. The numerous flower buds appear from late summer. The flowering itself usually takes place in March-April, depending on the climate and weather conditions, and lasts about 3 weeks. The flower buds open into small round flowers, which are clusters of bright lemon-yellow stamens arranged on long 10cm (4in) spikes, solitary or paired at the axils of the leaves located towards the ends of the branches. They are scentless.

Its evergreen foliage consists of large, leathery leaves called phyllodes, which are ovate-lanceolate to linear in shape, alternate, narrow and 5 to 20cm (2 to 8in) long. The lamina is dark green.

When planted in the ground, it can be placed as a solitary specimen, in a hedge, or in a shrub border. In favourable climates, it is often used to create a superb vegetal screen that is very useful for windbreaks, either alone or in the company of olearias, for example. It can be planted as a second row. It pairs well with other exotic shrubs such as Caesalpinia gilliesii, evergreen ceanothus, escallonias, or Grevillea, for example. To accompany its early spring flowering, it can be planted with Prunus triloba, Japanese quinces, or Teucrium fruticans 'Azureum'. It can be grown in a pot, protecting it from winter frosts in a lightly heated greenhouse or conservatory.