PlantFiles: Blue Dracena, Broad Leaved Cabbage Tree, Mountain Cabbage Tree
Cordyline indivisa

Zone 9b Coastal Otago, New Zealand
You definitely need luck to grow this wonderful cordyline; I live just a few kms from its natural habitat in NZ and I have trouble! Give it exactly what it likes and you wont have to lift a finger- but get things wrong and it will sigh and languish and do nothing for quite a few years before dying on you!
Its leaves are much wider than C Australis and the centre rib is often yellow. It usually keeps a single head though injury while growing will sometimes result in multitrunking.
The last person's advice was sound- it is a plant of moist evergreen podocarp hill forest and doesnt appreciate solitary exposure, blasting summer heat, drought or nurient-poor soil. It only LOOKS tropical. Half day shade is good, and it likes the company and protection of evergreen companions of similar height. Mulch with leaf litter and manure/seaweed tea, and do not disturb the roots while young.
It is worth fussing over- my first attempt failed but Ive learnt a bit about them since then. They are singularly elegant and are a knockout planted en mass, or in rows.
I can add that the NZ cordylines will *tolerate* pot culture, even doing well with conscientious watering and feeding, but plant them out if you can- they are happier in the ground.

The true broad-leaved Cordyline indivisa is a cool-growing mountain plant that is not tolerant of dry or warm-summer areas. In the U.S., its culture is mainly limited to the Pacific Coast fogbelt from Point Conception, California north to about Cape Blanco, Oregon. It is very slow growing and rather unforgiving of mistakes in caring for it when young. Good specimens may be seen at the UCSC Arboretum in Santa Cruz.

San Antonio, TX
Originating in the mountains of New Zealand, spikes in the zones listed are evergreen. In cooler climates, it must be placed indoors or in a greenhouse. It tolerates almost any light condition and any well drained soil. Last winter while growing in containers, my spikes withstood 20 degree weather and a very late spring freeze with no ill effects. Some state that it is a moderate grower, but my spikes grew from 8 inches to 2.5 feet in heighth in one year. Although it can eventually reach 8 to 10 feet in heighth, as a container plant, it can be kept smaller. In its native environment, a heighth of 20 feet is not unusual. Most spikes that are available in Garden Centers are small immature plants and they are used to add interest to mixed container plantings.

Potential pests and diseases are rare; however, on occasion, spider mites and thrips may be a problem. My plants have been free of these insects. I use them as backdrops to container grown annuals and because you are able to "see through" them, they do not block the view of other plants behind them. Adding a tropical look to the garden and providing great texture, I highly recommend spikes, in fact I am planting more of them in my landscape.