Cordyline Australis: A Tropical Palm Tree for a Cooler Climate
A Tropical Palm That's Not a Palm
Cordyline australis, the cabbage palm tree from New Zealand, is tough as old boots. It can survive snow, frost, high winds, salty winds (from the sea) and is a popular tree to be planted in promenades in Europe and the United States. Yet, it is not a true palm tree.
If you live in USDA zone 8 and above, you can grow this tree in your yard to give it a tropical look and feel. It requires a sunny and open position, away from undergrowth and hedging plants that may reduce its light, water and space. Though drought-resistant in their native New Zealand, they appreciate rain, as well as the warmer winds afforded by a seaside position.
Cordyline australis is a long-living, attractive tree, which is an asset to any garden.
Characteristics of the Cordyline Australis
The Cordyline australis can be grown from seed, by taking trunk cuttings or by lopping off the suckers it throws out from the base of the main stem and planting them in sandy, free-draining soil.
The adult tree flowers every other year, with creamy panicles of sweetly-scented flowers. The scent attracts a wide variety of insects, and this ensures pollination.
In the autumn, small hard berries form, which are irresistible to birds. The birds fly off and disperse the seeds when the remains of the berries pass through their digestive tracts. These seeds readily grow into new cabbage palm trees. Thus, it is a good idea to recognise the baby plants, so that they can be safely removed if growing in an undesirable area.
In my Dad's garden, both the cabbage palms and the pampas grass self-seed all over the place, and both look identical when they first sprout. You can easily tell the difference by running your forefinger and thumb down the edge of one of the grass-like leaves. The edge of the pampas grass is rough, whereas the cabbage palm is smooth.
How to Grow Cordyline Australis From Seed
I've grown a few cabbage palms from seed. Here are some important tips:
- Collect the ripe berries from the trees in late autumn or early winter and store in a cool, dry place.
- In early spring, carefully plant each berry to its own depth in the surface of a compost-filled pot and water well.
- You can pop the whole pot inside a sealed plastic bag to retain moisture or else give the pot a little water every few days to prevent the soil from drying out.
- After a couple of weeks, sometimes longer, you will see the seed germinating and the little plant pushing its way through the surface of the soil.
- Move the pot to a light place and keep well-watered, moving it to a larger pot as it it outgrows its existing one.
- Take special care not to damage its roots, and keep disturbance to a minimum.
Cordyline australis has a taproot, which, if broken, will result in a complete failure to grow. When it is a couple of feet high, plant it in its final position in the garden.
It is really important to give extra water daily to your young cordyline australis during hot, dry weather. Adult trees can survive drought, but young ones struggle.
Choose a Proper Location
Before you plant your cordyline out in the garden, make sure the position is suitable for it, as they cannot later be transplanted. They have a tap root, and while it is theoretically possible to dig up and move a tree that has a tap root, in practice they seldom survive. Growers will keep their cordylines in pots, thus avoiding this potential problem.
As I said earlier, Cordylines are tough as old boots and will survive most positions, so long as you have left them room to grow and a direct line of sight to the sun. Severe frost may kill your plant, though. So if you live in such an area where this occurs, you may find your plant will not survive.
If you have a high-ceilinged conservatory, this plant will look wonderful growing there in pots over the cold winter months.