Shrubs for heavy soil border north facing

Hi

I have dug out some old woody tall lavender shrubs from my front garden in the back border and I don't know what to replace them with. I have hedging all round but I want to make the back border really deep. I want to put in a row of shrubs that will grow up to 1.75 - 2 metres max and then gradually taper down and use bulbs and seeds too.

I already have a big virburnum leather leafed shrub in the centre. What else can I put in there that should work ok? I quite fancy ever greens so that there is something there all year round,but I also like plenty of colour and interest. Quick growing would be a big bonus to an impatient gardener too.