Choice of perennials
I need some advice on choosing a range of perennials for my garden. We recently had the lawn removed and replaced with slate chippings (the lawn was totally overrun with moss; my grandad didn't believe in removing old turf before laying new, go figure and poor drainage meant replacing with new turf was a no-go) and this summer we had a variety of wild flowers and Lobelia in pots. They've been really successful but now I'm looking at the future.
I'm looking at replacing the annuals with a range of perennials to give plenty of colour over the year from spring till autumn, but I have no idea what to use. Could someone give me an idea of where to start with regards to choosing plants?
Thanks in advance,