On the top level you could grow both edible ginger and turmeric. Growing these plants will allow you to enjoy their flavours in your food from your own garden. They would also give you a background level for the whole garden. Some of the cherry tomatoes would also give you a ground cover and plenty of fruit on another tier. Checkout the lovely grevillea ground covers on the net. The bottom tier would be soft with some of the grevilleas available.

I love the idea of using a mix Jadownes! It's funny, before starting work for this company I probably would never have considered using artificial plants for anything... I think for me I always had the mentality that fake plants didn't look very good or weren't capable of looking very good. But now.. I love the artificial plants! Of course though, If I had the time, space and ability to use real plants for my vertical garden I would in a heart beat! I think they look good regardless of which way you go and they offer a unique solution to creating some breathe taking spaces!

Not sure how it would go in Brisbane but what about trying a conifer? They grow fast and very tall. You can shape them or leave them natural. They are plain and certainly not tropical. Maybe speak to a local nursery and find out if they would grow in the sub-tropical climate of Brisbane first, as they are usually in colder climates (Sydney and south). Leightons Green Conifer – Leyland Cypress http://www.evergreengrowers.com.au/shop/hedging-screening/leightons-green-conifer-leyland-cypress/ Your quite limited if there's not enough sun and you dont use bamboo or tropical plants. Many other screening plants or hedges wont get tall enough for that space and climate. I hope you find something.

I love to mix artificial plants with real plants. I'm not a green thumb, so this helps a lot. There is a business in Perth called Everlasting Greenery, website http://www.hostwin.com.au They stock a huge range of artificial plants, trees, bamboo, flowers. I checked the website, they ship all over Australia. Please see attached photo of one of the plants, mixed with my real plants.