30 May 2014
Cordylines - Like Having Palm Trees in Your Garden
The cordyline, or cordyline australis to give it it's full name, is frequently seen in coastal and city locations, used for it's exotic palm-like appearance. It is also often used for bedding and in containers, and can make a good house or conservatory plant.
Cordylines have a height and spread of 3-10m (10-30ft) or more, by 1-4m (3-13ft) so can grow into quite large specimens. Most cordyline species are woody-stemmed, evergreen shrubs grown for their attractive foliage in shades of green, purple and bronze. They gradually loose their older leaves, leading to the plant's palm-like appearance.
Although not fully hardy, most mature specimens usually survive winter outdoors in milder regions or urban areas.
Planting should be done in spring to allow the plant to get established before winter. It prefers a sunny, sheltered position and fertile well-drained soil, though varieties with coloured leaves are best positioned in light semi-shade as the foliage can fade if exposed to strong sunshine.
Cordylines are suitable for container growing, using multi-purpose or loam-based compost such as John Innes No 2. Plants with coloured leaves should be kept out of direct sunshine. Tender species such as Cordyline marginata, C. stricta and C. fruticosa (syn. C. terminalis) are suitable for containers.
Plants should be well-watered during the growing season, but sparingly in winter, and benefit from a monthly feed with a balanced, liquid fertiliser from spring to late summer.
Though frost hardy, young plants, and also those with coloured foliage are more prone to cold damage. Tying up their foliage will reduce wind damage to leaves, and will prevent water sitting around growing points leading to rotting. In particularly cold areas try wrapping the trunk with layers of fleece, and protect the root area with a good layer of mulch.
Container grown plants should be moved to a frost-free location, such as a greenhouse, during periods of cold or wet weather, or can be given temporary shelter in a shed or garage. You can also move them up against a sheltered wall and cover them in bubblewrap after first protecting their foliage with fleece.
Overwinter tender species indoors or in a heated greenhouse providing minimum temperatures of 5-15°C (41-59°F) - houseplants will need to be towards the top end of this range.
Plants will flower freely in suitable weather, and flowers can either be removed or left on the plant and cut out later when no longer attractive.
Cordylines need little regular pruning - just remove dead leaves and spent flowers. Remove dieback or winter damage just above a new sideshoot, or cut back to a sound point on the trunk (below rot and damage).
They respond well to hard renovation pruning, which should be carried out in spring. Cut back to sideshoots, basal shoots, or to ground level. Create multi-stemmed plants by removing the growing point before growth begins in spring. After pruning, feed with a balanced fertiliser in spring.
Cordylines can be propagated from seed, cuttings or suckers, and this is best done between April and June. Pot up individually using well-drained cuttings compost and ideally give them bottom heat.
Most Cordyline problems, such as spots on their leaves, are a response to stress such as exposure to cold wind, hail and winter wet. Wet and cold weather in winter, and drought and heat stress in summer, can lead to poor growth, yellowing and browning of the foliage or excess leaf drop. Remedy this by improving the growing conditions and by providing winter protection. Damage to the bark following a hard winter can also be associated with an infection known as cordyline slime flux.
Some cultivars which you might like to consider are:-
C. australis - a palm-like tree which in the UK can reach 3-10m (10-30ft) in height, with a spread of 1-4m (3-13ft). It has light green leaves, and panicles of white flowers are produced occasionally in summer.
C. australis 'Torbay Dazzler' - a compact cultivar which has leaves with distinctive cream stripes. Ideal for bedding displays.
C. australis 'Albertii' - has matt-green leaves with red midribs, cream stripes and pink margins.
C. australis 'Sundance' - has leaves which are flushed red along the midrib. Another compact cultivar for your bedding displays.