Where we plan to build the house there are quite a few xanthorrhoeas or grass trees and we decided to attempt to move them. Depending on the species, they either have vast taproots or a fibrous root system . We took the view that they would probably have the latter, being a coastal species.
We dug a deep trench around our first test plant and filled it with water. the trench was deepened and refilled over several days. Eventually the plant came out easily with the root ball intact.
We had prepared an area for the transplanted plants and had a hole ready to go. The plant was put back into the ground within 1/4 hour of being dug up, well watered in with sea weed solution and mulched. Most of the plants in the area have now been moved. We will keep up very regular watering this year and we will are confident of retaining these iconic Australian plants.