Philadelphus - Mock Orange

I consulted a gardening expert (on Three Counties Radio! Sat mornings 9-12) yesterday on my leggy philadelphus.
He said you can coppice these after flowering (Apr/May) to about a third of their height, and get fresh leafy growth for the next year. He suggested doing this every two years, taking only a third off each alternate year. Has anyone tried this?

Renewing philadelphus

Reply from Andrew Radgick

Philadelphus, as with any shrub or climber which flower in the first half of the year, make new wood this year and flower on it next year. So cutting back or pruning immediately after flowering will help keep it more compact without affecting the flowering. Cutting back to about a third of the current growth is a form of pruning on a neglected shrub. If you are concerned this may not work, try cutting back just some of the leggy growth and see how it reacts. I would also be inclined to feed it after the cutting back to encourage new growth.

Mock orange

Reply from Veneda Harris

The old varieties of Philadelphus are always best prunned fairly hard after flowering and to keep new shoots coming up it is also useful to remove some stems from ground level. The newer varieties tend to keep their flowers longer and are more compact and bushy and should be trimmed as soon as the flowers are finished cutting back to the new shoots which will already be appearing, This should be done every year.