Dianella - A Planting Problem

Jeff Howes

Dianella: Diana, the Roman goddess of hunting
caerulea: dark-colored, dark blue, cerulean, azure, sea-colored, sea-green

Dianella caerulea is known as Paroo lily (among others) and is an attractive upright plant with flax-like leaves to 60 cms high. Flowers are blue with yellow anthers and are borne on spikes to one metre high and are followed by globular bright blue-purple fruit. It grows from coast to the mountains along eastern Australia.

This species has many named forms and this article is about the cultivar 'King Alfred'. Some other forms are 'Cassa Blue', 'Little Jess', to name a few.

These plants grow quickly in pots and this presents a problem for nurseries if the plants are not sold quickly as they become very pot bound. When this happens nurseries often place the plants on sale at a reduced price and this means a great bargain.

However, you will have a few problems when you get the plant home. The first problem will be to remove the pot, because the roots that have grown through the drainage holes will prevent you knocking the pot away from the root ball. You will need to cut the plastic pot away from the root ball to get it out of the pot.

Left: The plant as purchased and very pot bound. Right: Pot cut away.

Once this has been done, you can cut away two to three centimetres of old damaged roots from the bottom of the root ball and plant as normal. A better idea is to cut the plant in half, tidy up the cut leaves and roots, repot with new potting mix and water with a seaweed solution - two plants from one. An even better suggestion, if you are game, is to cut it into four, clean up the cut leaves and roots, repot with fresh potting mix and again water with a seaweed solution - four plants from one. Being so hardy, they will quickly make new growth ready for planting out into the garden.

Left: Root ball cut in half. Right: A mature plant.

'King Alfred' grows well in full sun and moderately shaded positions. It tolerates salt laden windy positions and isvery drought tolerant. It lives on natural rainfall in most of the populated areas of Australia. The maintenance requirements for 'King Alfred' are low - it will only need trimming approximately once every 5 to 8 years if at all.

Australian Plants online - 2008
Association of Societies for Growing Australian Plants