Recently, a resurgence of interest in tropical bedding and an honest enjoyment of bold colours and shapes have seen plants such as cannas and dahlias welcomed back to the fold of the fashionable. The genus Cordyline is also enjoying renewed popularity and is currently being imported from huge Italian nurseries by the lorry load.
A recent RHS trial of Cordyline in containers was held at RHS Garden Wisley, offered the opportunity to study and evaluate one of the most useful and striking, but perhaps underrated, of garden plants.
Cordyline australis 'Atropurpureum' is the deep red or purple leaved form of Cordyline australis. It has been grown in California since 1902 when it was listed as cultivated in Baily's Cyclopaedia of American Horticulture.
This elegant specimen is a favourite for containers. For great impact, use it as contrast among plants with less dramatic foliage or as a focal point among colourful flowers. The long slender leaves and a slow-growing trunk make this an architectural plant that lends itself to modern interiors. Their evergreen leaves provide interest throughout the year.
Cordyline Atropurpureum make a strong vertical shapes, the deep purple colouring contrasts well with silver foliage and can be an excellent foil for the lush foliage of other exotica. They look equally at home in more conventional and hardy ornamental borders, often used when small to give structure to annual bedding schemes. They look good adjacent to other large foliage plants or some of the softer, gentle grasses which offset the hard lines of the leaves.
One of the most identifiable New Zealand native plants, they have a tropical air and can cope with temperatures down to –5°C (23°F). This cold loving species grow surprisingly well from seed and grows in all soils and situations. Although grown for their foliage, cordylines do flower. In mid-summer an large spray of small scented white flowers is produced followed by attractive, little round red or purple berries.
Sowing: Sow indoors at any time of year
Sow the seed in small pots or in seed trays in a seed and potting compost mixture and cover with 2mm (¼in) of compost. Keep in a warm temperature around 18 to 22°C (65 to 70°F). Germination 8 to 12 weeks (some may take a little longer). Be careful not to over water they can be susceptible to the fungal disease damping off.
When the seeds have germinated they can be pricked out into single three inch pots. Keep them in a very light room (greenhouse if possible). They need warmth to grow well, otherwise the roots struggle to take up nutrients and the seedlings turn yellow and die. Water sparingly until the seedlings are of a good size. You may wish to keep them in pots while young, as although they are hardy plants, for their first winter they are best moved into a greenhouse or conservatory for some protection while they are still young.
If planted early in the next summer, they will have made substantial new roots by wintertime and should be better able to cope with the rigours of our climate.
They prefer good light, but in very hot areas give them some protection from direct sun, under the canopy of palms or trees is perfect. Cordyline are slow growing, but if left to mature in time can grow tall, usually to 3m (10ft) in UK, but can grow up to 6m (20ft) high and 2m (6ft) wide in warmer locations. Plant 4m (12ft) away from any structure.
Before planting try and mix into your soil some well rotted manure and if this is not possible incorporate a general base fertiliser such as Fish Blood and Bone Meal. Addition of extra sulphate of potash enhances their colour. It is important that they are planted in a well drained soil - they do not like water logged conditions.
The plant can be cut back to reduce height or to force multiple trunks. It looks most natural if planted in groups. Three or more plants can be planted together in the same hole to produce this effect. Cordylines are very drought tolerant and can withstand the rigors of a fairly harsh environment. They work well in containers and are useful in dry gardens. They can tolerate coastal conditions if protected from direct sea winds.
The great thing about a tree in a pot is that you can move it around to change the mood in the garden, but a problem with containers is that they tend to dry out quickly. Use loam-based compost such as John Innes No 2 or 3 which are quite free draining, but do tend to hold water much better than many of the peat-based multipurpose composts. Add an extra ten per cent of sharp grit sand. You can also add water retaining granules. Add 12 month release granules and place gravel stones in the bottom of the pot to assist drainage. Cover them with fleece when very frosty weather threatens.
Two cordyline species make good houseplants - C. australis and C. fruticosa. In the wild they would both become trees, but do not attain these dimensions in the home.
For optimum growth water freely and feed monthly while in active growth. (or fertilise annually with a long term slow release fertiliser) Once established they will tolerate dry spells better than most plants. Established plants will tolerate a reasonable amount of frost, but the real killers are usually cold wet roots, or a cold damp head. In very cold regions it is worth tying the leaves up to the stem so that the crown is protected from the worst of the winter weather. Make sure that the foliage is thoroughly dry before you wrap it up for the winter. Use a forgiving material, such as fleece or raffia to tie plants so the leaves aren't bruised or cut.
You will find that the lower leaves will start to yellow and go brown; this is a natural senescing of the leaves and usually happens around October. They can be left on the plant or cut off close to the main stem with a sharp pair of secateurs or garden shears. Do not tear the leaves off as this can damage the main stem.
“E kore e riro, he ti tamore no rarotonga” - meaning “The cabbage tree is never carried away in a gale”. Referring to a person of courage being like a cordyline which can withstand a gale. In its native New Zealand it is one of the world’s tallest monocotyledon growing as high as 20 metres and reaching an age of several hundred years.
‘Ti kouka’ as the Maori call it, were prized as navigational markers. The very strong fibres in the leaves were used for fishing and are still used in craftwork for baskets etc.
For at least the first 800 years of Maori occupation of New Zealand they were a valuable food source. The new shoots of the tree were an important source of protein and eaten as a vegetable. Their high carbohydrate content can be made digestible by cooking. Inner pithy fibres of the trunk can be dried and cooked into porridge, the stems are sweet. Their high carbohydrate content can be made digestible by cooking. Beer or wine is made from decoctions of the roots.
The Maori made use of its medicinal properties - healing sores and cuts and as a cure for dysentery and stomach pains. New Zealand is testing the tree for use as a crop for fructose production trialing the Maori tradition of coppicing C. australis as a perennial stem crop.
The name Cordyline comes from the Greek word for a club ‘kordyle’, referring to the enlarged rhizomes. Often referred to as a palm, they are actually members of the Agave family, Agavaceae
The sub-species name atropurpureum means 'very dark purple', The word 'atro' is a prefix conveying the sense of 'blackish or very dark,' and purpurum means the colour purple. It is often used in species names, as in atrocaeruleus, 'dark blue' or atrococcineus, 'dark scarlet'
Dracaena australis, Charlwoodia australis, Dracaenopsis australis, Terminalis australis, Cordyline superbiens, Dracaenopsis calocoma, Cordyline lentiginosa, Cordyline veitchii, Cordyline forsteri, Cordyline calocoma, Cordyline sturmii, Cordyline calocoma
The genus Cordyline is much confused with the closely related species Dracaena. The foliage of Cordyline can to the untrained eye look like the foliage of some Dracaena species, hence the confusion. One quick way to tell if you have a Cordyline or a Dracaena is to look at the roots.... Cordylines have white roots and Dracaenas have orange roots. Dracaena are not hardy in the UK
The leaves of a cordyline grow in a rosette circling the central stem. This distinguishes it from the similar looking Phormium (New Zealand Flax) which produces its leaves in a fan shaped arrangement.
- Additional Information
Packet Size 10 Seeds Family Agavaceae Genus Cordyline Species australis Synonym Dracaena australis, Charlwoodia australis, Dracaenopsis australis, Terminalis australis, Cordyline superbiens, Dracaenopsis calocoma, Cordyline lentiginosa, Cordyline veitchii, Cordyline forsteri, Cordyline calocoma, Cordyline sturmii, Cordyline calocoma Common Name Purple Cabbage Palm Other Common Names Cabbage Tree, Torbay Palm Hardiness Tree Hardy They can cope with temperatures down to -5°C (23°F). Flowers Large spray of small scented white flowers Natural Flower Time Mid Summer Fruit Small red or purple berries Foliage Deep red-purple strap leaves Height 10m (33ft) Spread 3-4m (10-13ft) Spacing Plant 4m (12ft) away from any structure Position Full sun to partial shade Soil Any but prefers deep humus rich free draining. Time to Sow Sow indoors at any time of year Germination Germination 8-12 weeks at 18-22°C (65-70°F). Notes Often used as a shrub. Medium to fast Growing.