Black Knight Cordyline

Black Knight Cordyline (Cordyline australis 'Black Knight') is the plant to reach for when a narrow space needs a strong vertical line. It grows to about 3m tall and only 1.5m across, holding a fountain of deep burgundy black strappy leaves on a slowly forming trunk. The colour is dark enough to read as near black against a rendered wall, and it stays that way all year.

Why you'll love it

• Dark foliage that holds its colour. Deep burgundy black leaves year round, with no autumn change and no seasonal fade to plan around.
• Tall and narrow. About 3m by 1.5m, so it delivers height in a garden bed barely a metre deep.
• Very little upkeep. Pull off the spent lower leaves once or twice a year and that is the whole job.
• Handles exposure. Frost hardy, drought tolerant, wind tolerant and salt tolerant, which is a rare combination in a feature plant.
• Scented flowers on mature plants. Older specimens throw large sprays of creamy white flowers that bring in nectar feeding birds.

Where it works best

Feature planting. One plant against a pale wall or in a bed of grey foliage does the work of a small tree. In a row, set them 1.5m apart so each keeps its own outline.

Pots, balconies and courtyards. A pot 500mm or wider suits it, and container growing naturally holds it nearer 2m. The narrow footprint is what makes it work on a balcony.

Coastal gardens. Salt and wind tolerance mean it holds up on an exposed block where softer feature plants shred.

Growing Black Knight Cordyline in Australia

Position and climate. Full sun gives the darkest colour; in part shade the leaves turn a lighter bronze. It suits subtropical, warm temperate, cool temperate and Mediterranean gardens and is frost hardy once established, though young plants appreciate shelter through their first winter in cold districts.

Soil. Free draining above all. It grows in sand, loam or improved clay, but sitting in wet soil over winter is the one thing that reliably kills it. On heavy ground, plant on a raised mound.

Water and feed. Water weekly through the first summer, then only in extended dry spells. A single application of slow release fertiliser in early spring keeps the new growth strong.

Pruning. None required. Strip the browning lower leaves by hand to reveal the trunk, or leave them as a skirt. A plant cut back usually reshoots as several heads rather than one.

What to expect when it arrives

It is grown as tube stock and in packs of six 200mm pots. Both are young plants: a tube is typically a small fan of leaves under 20cm, and a 200mm plant is a fuller rosette with no trunk yet. Cordylines travel well because the leaves are tough and the crown is compact.

Expect the trunk to take a few years to form, with most of the early growth going into leaf and root. Plants are delivered Australia wide, with delivery from $29.95 and a minimum order of $300 before delivery. Every plant carries our 30 day healthy plant guarantee.

Plant care guides and related reading

• Using cordylines in the Australian garden
• Compare the full cordyline range
• Other plants for coastal and salt exposed gardens
• Narrow plants suited to balconies and courtyards

Common questions

Is it safe around cats and dogs?

No. Cordyline foliage is toxic to cats and dogs, and chewing it can cause drooling, vomiting and loss of appetite. Choose a different feature plant if your pet regularly chews leaves.

How much frost will it take?

It is frost hardy once established and copes with the frosts of most southern and tableland gardens. Young plants in their first winter are the vulnerable ones, so mulch the base and give them a sheltered spot.

Why are the lower leaves going brown?

That is normal ageing, not a problem. Cordylines shed their oldest leaves continuously as the trunk extends. Pull them off with a downward tug or trim them at the base.

Will it grow in a pot long term?

Yes. Use a pot at least 500mm wide with free draining mix and expect it to settle around 2m.