Hard pruning philadelphus?
With all this time at home one of my neighbours decided to cut back her old hedge back to reduce the width, but in doing so she's found three philadelphus shrubs inside it. Heaven knows how long they've been hidden but they're now fully exposed and she wants to improve them. All three are about 6ft tall with leaves on the top 4inches only. One has only one stem (about 1.5inches diameter) which forks halfway up, the other two have two branches coming from the base (again about 1.5 inches dia). All three have lots of twiggy branches with sparse leaves, but only in the top 10-12 inches where they were at the top of the hedge and managed to get to the light I suppose? Our question is how to bring them back to healthy, bushy shrubs. She's loathe to cut any stems back hard as there's hardly that many there already! And we're not sure new growth will come if they have a sudden hard prune. Any help would be much appreciated. She really doesn't want to remove them as she's so pleased to have discovered them. Many thanks all.