Posted: 29/04/2013 at 17:03
I'd sow some more! Plenty of time & the later sowing will romp away/catch up & look more healthy.
MG really sulk if the nightime temps too cool, so I never sow until early May. Learnt the hard way.....
You also said that they were on a N facing sill..... definitely too cold for them. Sorry, J.