Vim, do you mean the part in the middle or the outside of the turf?

Hi, have a look at catalpa bignonioides Nana it is a magnificent standard , a real feature and grows beautifully in Melbourne, would look gorgeous in your garden.

Or you could try Lilly pilly , viburnum or photinia ‘red robin’ or iceberg roses

I would like to plant out side the turf area. ( Inside white stone box) Thank you so much for your recommendations.