How about a couple of grasses at the back of each triangle. Maybe Hostas in the shady side and then summer bedding and spring bulbs in the sunnier parts. Then, visit some open gardens and see what plants you like the look of. Climbers against the fence would be nice too. I staple bean netting to the fence to give them something to cling to. Try Clematis or Trachelospermum jasminoides (very scented) on the sunny side.

I've only just seen this post, so sorry for late response. This is difficult, so I'm still thinking about it, but I'm wondering, given the minimal depth of soil, hard substrate, the relatively small size of the planting areas and your health, whether it might be best to plant four or six rockery/dwarf conifers to provide evergreen interest year round, such as Picea glauca albertiana 'Conica', Juniperus communis 'Compressa', Chaemecyparis pisifera 'Boulevard', Chamaecyparis lawsoniana 'Minima Glauca', Abies balsamea 'Hudsonia'. Then you can use perennials for flowers - Geraniums such as Wargrave's Pink in the shady bits, Erysimum 'Bowles Mauve' in sun, dwarf lavender, Campanula persicifolia (half sun half shade). Coreopsis grandiflora is another good perennial for sun, with a long flowering period, but they are shortlived, and the same goes for the Erysimum. More suggestions include Aquilegia, Liriope, Physostegia, Potentillas such as 'Gibson's Scarlet', and another small shrub - Spiraea 'Goldmound' might be okay because it's reasonably small. Rockery Geraniums too, such as G. cinereum, have a long flowering period, but prefer sun. Otherwise, summer colour can be provided by bedding annuals, and pansies or violas. Verbena bonariensis (perennial, but often dies during winter and seedlings pop up) will give some height, though Verbena hastata (very hardy perennial) might be a better choice, reaching 3 or 4 feet.

Hi guys.Thanks Bamboo and Voluteer for your comments i will be taking notes on your sugestions.I have six Golden Crest Conifers (still in pots at moment about 14ins high),Would those be any good against the fence three in each bed.Do i need to treat the soil with anything before i plant,Are chicken pellets any use or do i need something else(If anything).Can i print these comments or do i have to write it all down,(Just a thought)Well guys i think that apart from treating soil and Golden Cres Conifers i am ready to make a trip to Hollybush Garden Center.Thanks again will keep informed on progress,Will post pics as i go.Cheers..

Having re-looked at the picture, I would dig the ground level soil before filling it up with soil to the top of the wood. Otherwise roots may have difficulties getting any further down.

Your conifers might survive, but they'd really need deeper root room than a foot, so unless they're able to penetrate the substrate (which they might), they'll die off. As for the chicken pellets, they're very good, but shouldn't be allowed to come into contact with plant roots. Add fish, blood and bone at the bottom of each planting hole.