Unfortunately from personal experience, developers cant be bothered doing any external work properly. It is a field beyond their capability! You should see some form of holes at the bottom of the walls or an agricultural pipe from behind taking the surplus water to a lower point. I doubt whether drainage has been addressed. Considering the height of the overall wall depth, you will need to consider this. Backfill against the walls should also not have been solely dirt. Drainage will need addressing, and the sloppy presentation of the flat areas I.e. uneven ground, before you address planting. THEN you consider the plants to use. Alison

I also agree you windows work together quite well, although I do see your concern from ground floor and first floor. I think it's a matter of proportions. I thi k this style of architecture is best complimented by elongating the details, in particular windows under eave line. In your case, the windows full height are striking, but as you cannot possibly achieve the same position being your external walls are different lengths, then I would create identity of their own, either by UN matching the style, or the layout. I like the full height from the interior, however, perhaps on the right, I would adjoin the window to the central panel, and extend it across with the glazing bars on the right, leaving the adjoining window a fixed, open pane of glass. Lave the same width of wall exposed on either side working from the outside in, that way the sight lines would be improved, and each room it's own unique vantage point. For the ground floor, again, elongate them, shorten them, and lift as high as you can, it will improve sunlight exposure, and provide useful wall below them, form he inside built in joinery can really impact your interior. Bookcase, window seat etc. I would also keep them as a single pane but with the top section divided and awning opening. So effectively, two rectangles, small one on top, larger pane below. As for your feature area, would make it something that links into the window frames, architectural, so perhaps a nailstrip ethical cladding in a colourbond grey, or if budgets allow, a copper cladding panel. It will age beautifully, and I would uplight it rom your portico so it is really a beacon of welcoming. Infact, I would continue it down below the portico, as if defining this central detail. The front door could be painted to match this element. I can even see a really stylish opportunity to use this portico roof, and clad the front columns in horizontal slats up most of he way, leaving he top boxed out to plant with cascading, heat tolerant plants. Striking and architectural, use landscape to create vistas from inside, and up light to dramatic effect. Plants like mother in laws tongue, ground covers and cascading dichondra falls, all will soften the architecture which can remain unapologetically bold.

Couldn't give enough paw paws away - they produced so many so fast. Capsicum and tomatoes were fantastic in my raised garden beds. Haven't bought any herbs all summer -growing those is just so easy. Had plenty of out of season leeks and garlic too. Now my orange, lemonade trees, and pomegranate are topping up my fruit requirements. Looking forward to my year old avocado and mango fruiting next year? I never. ever use pesticides. Don't mind sharing a few things with the pests, and happy knowing we eat organically. Thinking a couple of chooks as next on the agenda, but will have to train my dog not to chase and kill them. Just love my quarter acre block garden. Bought this house just for the garden, and that's the truth. Not too keen on many of the house features, but can't get decent sized gardens in the city any more unless one pays a small fortune [which we don't have]. We're still less than an hour from the city, and local needs are well met in this area south of Perth.

None of the suggestions so far, hit your brief which was for a lush tropical vibe. Nearly all the plants suggested are for temperate gardens. To create the tropical vibe it's all about the leaves. Luckily you have the perfect orientation for just such a garden. Here's my pics. Along the top of your retaining wall plant Alocasia, otherwise known as elephant ears. These are essential in a tropical garden as you need big leaves for a lush look. Alocasia come in many varieties and lots of different colours. Choose the one you like best. They grow in part sun, but can tolerate short full sun hours and nothing looks as tropical as these babies. Alocasia do send out runners so if you don't want them spreading up there you can pot them up as pictured. Putting these up high will create a canopy-like feel of big jungle leaves. Next you need smaller leaves and colour, enter an Indonesian tropical plant that is very popular but in your climate will do best with only morning sun. Croton. These are everywhere in QLD and other subtropical gardens. They are slow growing so you never need to trim them and top out under 2 meters high. They have the best colour when planted under taller plants where they receive dappled light for short hours of the day. Too much sun and their leaves bleach. They come in many different varieties, many colours and leaf shapes. They are a beautiful low maintenance plant. Croton do great as a potted plant as well. It's not a tropical garden without a water feature. I favour still water features which are simple to put together. The most expensive part will be the glazed bowl which depending on size can run about $200 but it's a one off investment. One of these with either a water lily (not lotus it's too big) or a papyrus, throw in some frogbit which is a floating water plant and you'll have this.... As long as the bowl is less than 30cm deep you won't need council approval or a pool fence. This particular bowl is growing a sedge (tall grassy stuff) arrowhead (the triangular upright leaves, you can eat the bulbs) a small water lily and a canna. Perfect for a tropical vibe. For something to cascade over the edge I'd avoid the Dichondra silver falls pictured in other answers. They create a dry climate rather than tropical look. Great tropical cascaders include... Syngonium, you can get this at any garden centre or take a drive around local parks it's often growing wild as a garden escapee. It's very easy to strike. Just pull of a section with a bit of root attached and stick it in your ground. Hoya, or wax vine. Few things look as tropical. Also very common in garden centres. Or another option is to grow this native, DIanella silverstreak all along that retaining wall and let is cascade over the edge. It grows full sun to part shade. It's easy to buy in bulk for a mass planting. Once you've got the big stuff planted up, you'll have patches of sun and shade that you should fill with creepers and other low growing plants that take your fancy. Silver Lady ferns are hardy and look great in a shady spot. You cannot go past a birds nest either as they famously take even full sun without burning. This ones growing with caladiums (miniature type of elephant ear in very colourful variations and a grass. While single plant mass plantings look great around hotels and public parks. A backyard is much more interesting if you mix up the plantings with carefully chosen combinations that create height, big leaf drama, colour and texture. Tropical gardens can be very cool. Look at all the different heights, leaf colours and textures here. Creating the tropical look is about creating a canopy effect with some tall plants, big leaves, coloured leaves and creepers. PS - Forget about bamboo. Someone planted 20 clumps of the stuff in my garden, it's ugly and impossible to remove as the rhizomes are like concrete and need a bobcat to dig out. What people don't tell you about clumping bamboo is that the clumps continue to get larger and larger taking over your garden. It also regularly goes through periods of looking awful.