I am in Australia but a weed is a weed and I agree with Design Solution Group, that I too just pull by hand, unless there are too many rearing their ugly heads, as is the case right now with Spring upon us. I mulch very heavily with wood chips or similar but the weed seeds still blow in from all over the place, so if you think by mulching, you'll have no weeds you're kidding yourself but the amount of weeds to deal with, will be, with good mulching, about 10%, so it's definitely the most important thing any gardener should do, especially, now that many of us have a ride on mower instead of a push mower, we tend to be quite extravagant with the area of garden we now have versus say 50 years ago. I have to say that for me, at this time of the year, I simply don the backpack or hold the hand sprayer, a little Zero or Roundup and a shield on the end of the spray nozzle to protect against drift, and I'm off to spray and I spend perhaps an hour and save allot of weed pulling by poisoning these weeds. If I tried to pull these same weeds, it would take me approx. 2 - 3 hours on my knees to save my back. Just to let the readers know also, that the chemical I've mentioned with Glyphosate being the active constituant, is very safe to use and in fact when my husband, a farmer, did a compulsory chemical handling user course, he learned that this chemical is almost safe enough to drink without actually doing that, safer to use than the hair dye we women use to colour our hair and is safer than a very popular diet drink that if consumed to excess can cause death. So don't be afraid to spray to help lighten the burden of excess weeds at times, less weeds means that the plant you are nurturing and has at times cost many dollars, doesn't have competition from the weeds for nutrients and moisture. It is also an interesting fact that weeds, like simple grass if it's in the wrong place is still a weed, puts out a toxin surrounding it's root system to try to kill its nearest rival to protect itself from peril!! I have attached a photo of an area of my still newish or young garden taken last spring, as I now have another rather large plant bed to the left of the picture. This area is the smaller section of my front lawn and I have also attached photo's of my bulb/flax garden beds, of which there are 5 up the driveway, an early photo of my small cactus garden and a garden area around my fish pond, also an early photo with the plants now quite developed. I honestly do not have allot of work even with all this area with the biggest job once a year being, having to pull all the dead branches from my 40+ flax plants. AND Watering during summer would be the longest ongoing job in my garden!!!

Perhaps check with your local council to see if they have a plant list. Many councils here in NSW do this to assist homeowners with choosing native Australian plants and some introduced plants that grow well and are in keeping with the area. Of course it depends on the look of your house and whether your landscaping plan will compliment that, or whether you want a manicured look, or a natural look, cottage garden look (e.g flowers and hedges) or a beachy look (e.g. if you have a pool) and so on. Fruit trees sometimes need a different aspect to other trees, so separating food trees from general foliage is something to consider. Oleanders are off the list in many parts of NSW too. We recently put a fence in similar to yours but it has been painted black as our house is modern. We've been advised on lomandra, banksia and grevilias and lili pillys for a native garden as we already have lemon scented gums and ironbarks on the property. If you consider the building style of your home, and the trees common to the area you're in, sometimes that can give some inspiration

Thank you all for your comments. Well, it's been a few months since my original post and we have since finished putting up the retaining wall and planting the hedge. We decided to go ahead with Murrayas - planted about 34-40 cm apart. I gave them a good trim about a week after planting at the end of Autumn and another quick trim at the start of Spring. They have really filled out in warm weather and I think the gaps between individual plants should close by the start of winter. I'm really happy with the choice - the hedge looks glossy and lush and the sweet smell of Murraya flowers is just beautiful. We didn't do any underplanting, but I'm still thinking about putting in the dwarf agapanthus for the inside border. A couple of weeks ago we planted some Rhaphiolepis "Snow Maiden" and Rhoeo along one side of the retaining wall to provide a border for a footpath and I'm really happy how it turned out.

Your site is far too exposed for Maples. They are small trees that really need to be buffered from winds and too much sun by other plantings. They also need the soil constantly moist which will be nearly impossible on that slope. You really don't want to grow magnolias anywhere near the footings of a house. Have you seen how large a tree they are? Since you are in a temperate zone and like autumn foliage I can recommend a gingko tree. It will be right sized for your yard and give you that similar lighter than air look and autumn colour as maples but it's more hardy. Another option are silver birches. I would hedge the boundary for privacy and also to cut down winds to your garden which will dry out the grass and scorch it. With that slope you are going to need more rocks I think to prevent your topsoil from washing away in the first rain. It's really no use of us to provide you a list of random plants. What you need to do is put together a series of photo's of gardens you like the look of, then find plants to match that style. If you don't plan gardens then you end up with the ubiquitous suburban patch of grass and odd bushes look instead of a lovely garden.