Hello, It looks like you have your work cut out for you. I would like to introduce our product that could be of use in your application. We manufacture Landscape Tanks. They are a Retaining Wall, Garden bed and Water Tank all in one. See Some example pictures below of how our tanks have been utilized in a similar application; To see more examples please click on the link below; http://landscapetanks.com.au/gallery/pool-surrounds-fences/

Thanks everyone for your further comments. No problem about it being an old post, always nice to communicate with people about design solutions/problems. Jilly, I posted some photos on 1st January 2016, they appear further up in the post. Garden Beet Pty Ltd, and Morel Construction Ltd, both of your solutions look great, but our problem still remains the western Queensland sun which is pretty vicious on anything that will either wilt, fade or break down. It was quite a difficult challenge to come up with something that was affordable, workable and durable. I would love to have had plants because I believe they soften large "hard" exterior areas, but we have decided that we will do that with pots around the pool area. Still have that to do, even after all this time. :) Thanks everyone for re-igniting this chat. Jilly, hope you find something that works for you.

Yes - there are these amazing options to have an 'electric pool cover' with a slat arrangement that allows you to virtually walk on it. Do a google search...'pool covers electric'... I've no idea on how much they cost... Here's some pics. Not sure if irregular shapes make this too challenging... Our pool experience... We are needing to change a few things with our pool already - wish we had paid more attention to the pipes and filtration... (Having to potentially move them as they are too shallow and in 'awkward spot'... Extra $ and I'm so worried it may cause issues for us... Even the location of the concrete slab for the pump... Wish we had thought about overall picture... If I was buying a car for $70k, I would have done more research, but somehow we got carried away with idea that we could have a pool for summer, and yet reality is that it's ready for the 'next summer'... Budget plan (original) was around $30-40k, but I guess it's like building a house... Plus it's all a big learning experience...

Hi Roger, With the pleached trees, I think your underplanting amps up the tropical look especially if you go with a magnolia that have the dark green upper leave and the bronze underside. You could just go for banana or palms - personally I think you might be right about the clumping bamboo becoming a bit dense. Regarding your 400mm retaining wall - citrus are shallow rooted and tend to have a root system that goes out to their drip line. Maybe if you put it in a corner you can use the corner to espalier it in conjunction with staking it to get upper stablility but I'm not sure how it'd go with the roots - but give it a go at $30-50 depending upon size it's not an huge amount if it doesn't do well - just dig it up (just watch the thorns) and give it to a friend - check out Daileys for varieties and maybe get in touch and see what they think, they might do them on a dwarf root stock - I've found them to be helpful in the past. i'd be reluctant to underplant any kind of citrus though - as they are shallow feeders.