Posted: 08/07/2014 at 19:55
Thanks for the reassurance, bekkie. I live in London and the garden is south-facing, so you probably are right.
I'll try and get some photos to post, nutcutlet. Perhaps my problem is that I cut back all of the spent flowers / foliage, and now it's exposed all the plants who seem to have been suffering (perhaps from the competition). (I too completely understand the bit about weeding...!). Also maybe I simply need to add some annuals for more colour, as you say...
Would it be a good idea to water the plants with some seaweed feed?
I also wonder if the compacted soil is part of the problem. I did loosen it with my own compost earlier in the year, but it's still become very compacted. Perhaps adding some more might help rejuvenate the bed?