Flower buds not opening problem?

A new problem for me, I had 2 14" baskets planted with Petchoa ( a type of Petunia ). Both were flowering OK when I put them out. Then the yellow ones buds stopped fully opening, soon followed by the red plants buds not opening. The plants looked fine except for the stunted flowers.
Now this Calibrachoa has developed the same problem. The plant looks 100% but the flowers below have not moved since Sunday.
I have green binned the Petchoas and isolated the Cally. Any ideas on this new problem to me,cures or prevention ?
TIA

 

Odd @HarryS .
Wonder if it could be a virus.
I guess you have checked for aphids etc.?

 

Hi,

Sounds as if it could just be they did not like the change in temperature or air stream when you put them out.. just enough for them to stop opening the flowers..?

 

Hi @HarryS I think we had the petchoa from the same place, mine seem fine at the minute, they are in pots awaiting baskets, I've Just got them in mpc and water them when they seem dry.

 

@mazambo , mine looked like that for a while !
@ricky101, some of the plants were in a very sheltered spot, and it has been very warm all the time they have been out.
@pete , I should have checked for aphids. I'll have an inspection tomorrow and give them a spray

 

Well I checked for aphids and no sign. I have trimmed all the flowering stems back by a third and given it a bug spray. The plant itself looks really really healthy. I am keeping it isolated from the other plants, and now only time will tell.