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.

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.

Congrats on choosing blocks for your garden bed. If you're looking for trees, I suggest considering a maple tree. They grow nicely over time, providing shade and privacy. I recently moved to a new house myself, and I'm also exploring plant options. Back in my hometown, we had a reliable tree service that helped us with planting and maintenance. Maybe you can find something similar in your area. I came across this website, https://www.deepdale-trees.co.uk , which might be helpful for you. They offer a variety of trees and services.

Every year I buy more bulbs to pot in various combinations. I bring the best ones inside when they're at their flowering peak. Grape Hyacinths and tiny daffodils with white and red freesias are my favourites so far. I love the scent of freesias, the brightness of daffodils, and the intricacy of ranunculus. I want to plant a big oblong tub of Ranunculus this year.