This rather beautiful Surfinia was sitting on our dining table at home yesterday (5/June 16).  As we have seen earlier with tomato plants in a greenhouse the Phytl Signs 50x recorded huge electrical activity from the plant from solar noon (2.00pm here in Switzerland) and for about two hours afterwards.  There was a chirrup every few seconds during this period.  It felt more distinctive than just the maximum of a diurnal cycle, more a distinct, intense period of activity.  The rest of the day and night was much quieter.