I attach a couple of pics for a weekly update. I fed them some epsom salts and have just given them some phospurus. It certainly seems to have stopped any rapid degradation so I'm hoping it's working. However, I don't think something's right with one of the plants, and I'd be really grateful for some further advice.
As far as I'm aware, both plants have been given the same amount of nutrients (I can't recall if they're all in multi purpose compost, miracle gro compost or a mix of both - I'll try remembering next time!), but one is seemingly very healthy and the other is definitely showing signs of some 'sickness'. I'm hoping that the leaf discolouration will be an obvious clue for an expert to diagnose exactly what the problem is. I'm not even sure if I'm over or under fertilising! I guess the latter as the more vigorous grower seems to be suffering, but I'd hate to guess wrong!!
Thanks in advance for any help that's offered.