@bigreader thanks also. I just came across Angus' site tonight. FYI the man at the nursery also suggested I do "succession planting" (assuming that's what you mean) i.e. put the lilly pillys at the back and put a row of ?cant remember the plant he suggested? in front that grows more quickly than the Lilly Pilly so will provide screening in quick time up to 2 metres whilst waiting for the Lilly Pilly to grow. I opted out of because really I want the screening to create/fill in the border around the property - the reality is that the trees won't really act as screening much at all for many years (the trees need to get quite tall!) as the house up the back is UP THE HILL so unless they come DOWN their backyard (which they rarely do) the screening is not really blocking any views into my backyard.

Also you may need to rejuvenate your soil, add mulch , a watering system so your plants will survive, we have viburnums in a very exposed condition , they cop cold , heat , storms and they cope well as long as they have water, mulch , good soil and the occasional feed in spring, grasses would cope well also plants with a silver/grey foliage handle dry conditions well.

Make sure you have good soil, add mulch, water crystals to retain moisture, slow release fertiliser to promote healthy growth, a watering system is a great way to save time and keep plants looking great. You could try for a tropical look by planting golden cane palms, elephant ears, the gorgeous Rhapis is elegant and gives good dense coverage and beneath trees the lush Xanadu’s foliage is beautiful, adding to the soil as above will maintain the garden beds in top condition.

We underplanted our ornamental pears with viburnum ‘Emerald lustre’ I just love this plant, it withstands all weather conditions and always looks great with shiny lush foliage, I would add a watering system so your trees and hedge don’t compete for water and it saves you time also.