Posted: 06/05/2013 at 08:13
marshmello - the seeds are proprietary F1s and develop fine. They then (as I said) develop this tough 'pinch' at the base of the stem and start to wilt.
Bob - I think that must be the problem. Even with window and door open the thermometer has been showing over 30 degrees some days and down to near freezing at night. I will sow some more but leave them outside.