Half of Knockout rose taken out

[Nyboy]

Don't know whats going on with landscaper this year. I have a 2 year old knockout rose that he mowed half off. The rose is very unbalanced now. When it is finished blooming I would like to try and get shape back. How much can I prune it down to? When is the best time to do heavy prune?

 

[catjac1975]

Just lightly trim it. I would not trim heavy until spring!