Sunday, 6 November 2011

Try growing: grass trees

Grass trees, or xanthorrhoeas, are one of Australia's most distinctive native plants and can be used as a feature plant in all but the smallest gardens. Species of grass tree that grow in the Illawarra include Xanthorrhoea arborea, X. australis, X. glauca, and X. resinifera. 
Xanthorrhoea glauca growing
near Carrington Falls
 All these species are indigenous to the plateau in the west of the Illawarra, and don't grown naturally on the coastal plain. But, given the right treatment and careful handling during transplantation, they can fairly easily be grown in suburban Wollongong. 

The keys to success with grass trees are that they need very well drained, sandy soil to survive, and hate having their roots disturbed. This means you need to be really careful when transplanting them from a pot into the ground, preparing the site with plenty of sandy soil and small pebbles if your soil is not sandy to start with, and cutting the plant out of its pot to avoid damaging the roots.

Young Xanthorrhoea arborea recently installed -
note the white pebbles on the ground and plant
Our soil is mostly heavy clay, and not naturally suited to grass trees, but we couldn't resist putting in a couple because they're just such amazing plants! We lost one X. glauca to fungal infection, to which they are prone, but the other plants are all doing very well, and one of the X. australis has even decided to start flowering. (Apparently it's better if you cut off any flower spikes that come up in the first year after transplant, so that the grass tree focuses its energies on growing roots.) 
Xanthorrhoea australis in flower - whoops!
Grass trees that are harvested from the wild (generally from areas where land is being cleared for housing or other purposes) will have had most of their leaves cut off to reduce the stress of transplantation. Over time, as they get established in a new position, they will grow more leaves again, and start to look more like they should. (Plants grown from seed will not generally have had leaves cut, and you can also be confident that they were not harvested illegally.) 

Grass tree two months after transplanting
The same plant after five months
To help grass trees adjust after transplantation, we found that daily watering for the first couple of months was essential, particularly during any periods of hot weather. Regular summer watering for the first couple of years after transplantation is also recommended.

For more information, try the following websites:



2 comments:

  1. Hi there! Great blog. Looking forward to following your garden transformation. Did you buy your grass trees from a nursery? Or were they rescued from land about to be developed? Thanks for sharing your knowledge of native plants!

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  2. Hi Mandysri, good to hear from you! We have mostly bought grass-trees grown from seed, from local nurseries. When we have bought 'grown-up' grass trees, they've come with a certification from the NSW Government.

    I recall seeing on Gardening Australia that it is possible to buy grass-trees that have been rescued from land slated for development, but I think these grass-trees would need to go through a certification process to 'count' as being ethically harvested in any case. If in doubt, I'd buy one with a state government certification.

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