Ok, a severe trim. In the past once petunias are past their prime I've tried cutting them back, to hopefully send forth new shoots and flowers. It's always been a fail.
This pot of some miniature variety of petunias was all I could find at the big green shed. They behaved really well but two and a half weeks ago when they were still looking good, I thought I would try the cut back, fertilise and heavy water. Maybe my former efforts failed because I left it too late.
So there is lots of new growth but I thought it would happen more quickly. No sign of flowers yet. I may have once again made a grave error.