Posted: 08/07/2014 at 19:59
It's never too late
Dianthus deltoides, a packet of mixed colours. Little bits of the small sedums could be poked in,
I had to look up the spelling of this one so you can have the linkhttp://www.rhs.org.uk/Plants/32487/i-Erigeron-karvinskianus-i/Details
Several of the little campanulas will grow like that.
lobelia, it's come up in cracks for years here.
Plants love gaps in paving