Growing Xanthorrhoea in Canberra
The grass tree Xanthorrhoea is an iconic Australian plant growing locally and all-around Australia. It’s famous for its distinctive black trunk and magnificent crown of ‘grassy’ leaf strands. When the grass tree decides to flower it will send up from the centre of the trunk a tall spike topped with masses of small white flower buds that open like popcorn, attracting both birds and bees.
Grass trees are extremely slow growing. From seed it can take up to 20 years to form a trunk. From there, it is estimated the trunk will grow 1-2 cm every year. So, when purchasing your grass tree, especially a tall one, you might well become the proud owner of a tree over 100 years old! Xanthorrhoea is a protected species. Harvesting from the bush must be done under licence and the trees are then tagged with a registration code. They may also be raised from seed.
What does Xanthorrhoea like?
• It is one tough plant, able to withstand drought, frost and even the intense Australian bushfires (which
encourage flower development).
• It does, however, like regular rainfall or moderate watering to help it survive.
• It likes full sun - at least half a day - but it can handle some dappled shade.
• Free draining, slightly acid soil - either a raised garden bed, rockery pocket or large pot is essential. It hates being waterlogged!
• No root disturbance, especially when planting. And because of its unique fleshy root system aim to retain as much of the original soil as possible. This is because the roots of the grass tree have a symbiotic relationship with microbes in the soil called mycorrhiza, which help the tree to grow.
Planting Your Xanthorrhoea
Planting in the ground: When you plant a Xanthorrhoea, choose a sunny position in very free draining soil. If
you have the shallow topsoil typical of this region, the best option is to choose or create a raised bed using rocks,
For the basics of planting into the ground, see our leaflet “Planting Your New Tree”.
Now two options:
1. Plant pot and all! Cut the base out of the pot it came in, to allow the roots to grow downwards, and carefully add some large holes around the walls of that pot to allow roots to grow out sideways. Finally, once you have lowered the grass tree into the ground cut the lip of the pot off. This option avoids disturbance of the roots and microbes. Fill in the hole with a mix of soil and compost and water in with Seasol, a sprinkle of chicken manure OR Healthy Earth fertiliser.
2. Plant the grass tree directly into the ground. You need to be careful to keep as much soil as possible from the roots intact and try not to disturb or damage them.
Planting in a pot: Transplant it into a large feature pot and follow one of the two options given above. Then fill up with native potting mix or a mix of native potting mix 50% and garden soil 50%. Please make sure there are drainage holes in the pot.
Xanthorrhoea like a little pure chicken manure once a year, a small handful sprinkled around the base as a supplement - a tip from one of our suppliers. Also give a regular light feed of Healthy Earth fertiliser. Dissolve a cup of brown sugar in a 9L water bucket or watering can and water the grass tree with it once a month for approximately two years while it is establishing it in its new spot or pot. The mycorrhiza microbes feed on the sugar, which helps the tree to thrive.