Yes, I agree Slang, natives are great however I have a lot of luck with succulents and cacti as they need little water and seem to thrive in our sandy soils -this time of year I can almost "see" them growing.
When the soil is built up with good-quality compost and mulch, almost anything can be grown in Perth. In my opinion it's the summer heat that's the biggest problem. Recently we've been focusing on native plants in our garden, which have been doing quite well. Others which have survived and flourished are toughies such as lavender, geraniums and even daisies.