Green wall design for shady spot

I have a 6ft L-shaped concrete block retaining wall creating a smallish sunken patio as part of my tiered garden.  It is very shady getting perhaps an hour of dappled sunlight in the morning and late evening. It is completely protected from the wind.  I want to hide it with a combination of evergreen climbers intertwined with something that flowers and maybe some shallow rooting annuals around the bottom - all the planting has to be done in planters/troughs as the patio is laid on bedrock. I don't want to take up more than about 2.5ft of depth for the planters and any trellis that might be needed. I also have the option of planting along the top of the wall into a soil border.  I am a stay at home mum with a 4yr old and a baby on the way so need plants that will pretty much take care of themselves and will put up with a bit of neglect  and aren't poisonous. Many thanks

I think I'd go with planting at the top in soil and have hanging, flowering plants that you renew each year as opposed to ...ivy growing up the wall.  I'm not an expert so someone might come along and say otherwise but the conditions you describe are tough so ivy would possibly survive but in troughs, you'd still have to water.  I have an ivy that survives/thrives in very little, poor soil but I suspect it searches under the house and patio beyond its small bed so it is not containerised.  Just my thoughts, hope it's helpful.

I have taken an interest in vertical gardening lately and I think this might also be an idea you could use, at least for some part(s) of the wall. If you follow the link you'll see what I mean  http://www.instructables.com/Vertical-Garden-1/                              

Maybe it would be a nice idea to have 3 of these devided evenly against the wall and fill the parts that are left with ivy that would be growing from the top or from the bottom in the planters you would like to see.  

EDIT: The link won't show you the instruction right away but if you look for 'Vertical Garden by Floddertje' you've got the right one. Sorry 

I understood the black dust on ivy was poisonous.  Is this a myth?

Ferns might be a good choice in this situation.  There is a Rosemary plant that tumbles down walls. Take a look at rockery plants which will tumble down.  Usually flowering plants need good light.

I used to have a small shady sunken garden so I can understand your position. I grew hedera colchica 'sulphurheart' up the wall. Its one of the ones with big glossy leaves - in this instance green with yellow variagation. It'd need some support at first, but will self-cling once it gets the gist. Tough as old boots but more interesting than common ivy. Also fiarly quick to get going, which many ivies aren't. Once its covering what you what an annual hack of anything spare and pulling out the odd brown leaf is all the maintenance it needs. You can underplant with evergreen plants such as heuchera, plus certain ferns are evergreen, euonymous fortunei is a small shrub that isn't fussy and comes in a gold and green variety, and perhaps the golden variagated sedge (carex) which also keeps its foliage all year. You can put a nice white daff such as 'thalia' under these plants and they'll just grow up through them every spring. Hardy geraniums will also grow in tough conditions, and whilst they're not evergreen, they do flower for a good long time - especially if you cut them back when the first lot of flowers is over - and it is nice to have a little bit of change through the seasons. Bedding will be tricky in so little sun - the non-dangly type of begonias should cope, as would violas/pansies, but that's probably about it. You could always squidge some into any gaps though. I used to have a couple of wicker 'witches hat' hanging baskets on my wall poking through the ivy. I put white muscari and miniature daff bulbs in the bottom, and then filled above with winter pansies. When the pansies were past it and the bulb foliage yellowing in late spring, I emptied the lot, dried out the bulbs to keep for the next year, and replanted summer pansies and golden lysimachia in. Not a lot of faff or expense but did brighten the place up!

Ivy is toxic if eaten, but my 3 and 4 year old boys never have. They knew from before they could talk the difference between people berries and bird berries. The colchica ivies tend to flower and fruit only when mature, mainly up high and usually in sun, so I wouldn't worry. They don't look appetising, either.

Thank you so much everyone for your advice.  I have read in the RHS plants for shady spots book that there are certain clematis that will thrive in little sun - do you think it would be possble to grow a shade tolerant clematis or maybe a honeysuckle through something evergreen such as the ones suggested by Betty so I get some summer/spring colour and scent as well as all year round green cover?  I am a sucker for flowers!! Advice on wether this would work in general and wether growing them together in the same trough is feasible and if so and how big it would need to be.

You could go for one of the smaller early 'large-flowering' clems, such as Nelly Moser. In general, the paler-flowered ones do best for shade. Or a small clematis alpina might do. There are gorgeous white ones. Anything bigger than about 6ft and you'll only get flowers up top, which would be pointless and frustrating, so choose on the basis of ultimate size. They'd need quite a bit of soil and water to thrive. Honeysuckles would be a better bet, being more tolerant of shade, drought an everything else. They also flower for longer. I'd let the ivy establish for a couple of years first, though, of the honeysuckle will out-compete it, leaving you bare patches in the winter. It'll also mean you don't need trellis for them, as they'll grow through the ivy. You could always buy the climbers now and keep them on wigwams in pot til the ivy's big enough to cope (if you're impatient, like me!). xx