Cordyline Australis

Class

Monocotyledonae

Division

Angiospermae

Family

Asparagaceae

Order

Asparagales

Genus

Cordyline

Species

australis

Description

An evergreen ornamental plant with elongated, linear leaves, arranged to form a distinctive clump, and with different colour tones depending on the variety, ranging from streaked green to streaked red and even bronze.
It is very well suited to indoor spaces such as homes and offices, as well as to terraces in temperate, frost-free areas. It can be planted in containers alongside other green plants with similar growing requirements.

It is also possible, depending on local climatic conditions, to plant it out in the ground, in full sun or partial shade, creating colourful, non-dense hedges.

It does not tolerate severe water stress, which causes the loss of basal leaves.

Curiosities and special features

Under the correct climatic and growing conditions required by the species, adult plants may flower, producing spike-like inflorescences bearing small, fragrant, cream-white flowers.

Origin and distribution

A botanical species native to New Zealand, where it grows as a tree in the subtropical biome; it was discovered in the late 18th century by the English naturalist and botanist Joseph Banks.

Cordyline has attracted widespread interest in both indoor and outdoor landscaping, leading to extensive hybridisation work which has resulted in a wide range of varieties that differ mainly in the colour of their foliage.

Leaf

The leaves have anelongated blade, ranging from lanceolate to linear, forming a large, spreading ‘tuft’.

Leaf colour

The variegated leaves give the Cordyline great ornamental value, making it a focal point in living spaces and offices, as well as in gardens and on terraces, provided the species’ temperature requirements are met.

Plant height

The plant’s height ranges from 0.8 to 1.5 m.

Lifespan

Perennial evergreen plant.

Stem

The stem is herbaceous and semi-woody; the plant has no thorns.

Flower

The flower is simple in form, small in size, with a bell-shaped corolla and single-coloured petals. It is arranged in spike-like inflorescences of medium size. It flowers from late spring to summer, with a flowering period of between 60 and 90 days. It has citrus notes, is unscented and has a delicate aroma.

Plant habit

It develops an erect habitus, visually reinforced by its long leaves.

Branching

non-branching

PH

It requires a slightly acidic pH of the medium, with optimum values between 5.8 and 6.5.

Ideal climate and temperature

The ideal temperature is between 18 and 26 °C. The survival temperature range is between 5 and 38 °C. Cordiline can be planted outdoors in the open ground if the climate is temperate and mild, taking care to protect it with non-woven fabric should winter temperatures be relatively low; if used as a houseplant, it can be placed outdoors once the risk of frosts – even late ones – has passed.

Soil

Use a soil containing peat, clay granules, lapilli and extruded wood fibre to ensure proper drainage of excess water, thus preventing water stagnation with subsequent root rot.

Growing tips

Some specific growing guidelines to help your Cordyline australis plant thrive:
Balanced fertilisation Avoid overwatering Keep the potting mix dry in cold weather Place outdoors once there is no longer any risk of frost It can be planted in a flowerbed, even in full sun. Requires little but regular fertiliser

Combinations with other plants

In large planters, it is possible to create mixed plantings with other species that have similar growing requirements to those of Cordyline, such as agaves and yuccas, creating visual effects with a strong ornamental impact.

Propagation

Vegetative propagation is carried out using tip cuttings for some varieties, whilst for others it is done using rhizome cuttings. Propagation via meristem culture, or micropropagation, is widely practised.

Watering

Apply low-salinity water directly to the growing medium, keeping it moist but not waterlogged to prevent harmful waterlogging, which can lead to root rot. The frequency of watering also depends on weather conditions throughout the different seasons: more frequent during the summer and less frequent in winter.

Avoid water stress, which can cause mite infestations and the loss of basal leaves due to yellowing.

During the hottest and driest season, light foliar misting may be carried out, ensuring that the water used is neither cold nor hard; furthermore, the leaves must be dry by evening to prevent the spread of plant diseases.

It is advisable to use a high-quality growing medium that ensures proper drainage of excess water.

Fertilising

It fears over-fertilisation, especially in connection with water stress. From spring until early autumn, add a specific fertiliser for green plants to the moist substrate, to be diluted in the irrigation water.

Edibility for humans

Non-edible.

Tip

If placed in areas with very little light, the leaves will curl up and the plant will stop growing. It can thrive in cold areas where the temperature does not fall much below 0 degrees, preferably in sheltered spots, away from heavy rain or in poorly drained soil if planted in the ground. Do not repot into soil that is too compacted and poorly drained.