 |
I would not recommend cutting the Mock Orange (Philadelphus coronarius) bush partially back as this will probably result in a bush with an ugly shape. It is best to rejuvenate the shrub by completely removing the stems at ground level over a period of two or three years, if the shrub is really overgrown. This major pruning job should be done in late winter (early spring) before the leaves emerge.
The first step is to prune out all of the dead stems, dead branches and any weak or spindly stems. Cut the dead stems and weak stems off at ground level.
In late winter before growth starts, cut about 1/3 or 1/2 of the oldest main stems off at ground level. Remove these stems in such a way as to keep the bush looking even. For example, do not cut all of those stems off on the same side of the shrub. New shoots will emerge from below or near ground level during the growing season. During the second late winter, remove another 1/3, or the remainder of the old stems by cutting them off at ground level. There will be a few flowers on the shrub from the new shoots produced the previous season, but do not expect alot of flowers until the 3rd growing season. Mock Orange produce flowers on wood from the previous growing season, not on the current years growth like roses or potentilla, for example.
Remove the final 1/3 of the old stems in the 3rd late winter, if you choose to remove only 1/3 of the stems each year, which in most cases is less hard on the shrub.
Once this operation is complete, Mock Orange are best left untouched, with the exception of removing any dead wood or thinning out a very crowded bush a little every 3 or 4 years by removing a few stems at ground level. The removal of a few of the older stems every 3 or 4 years keeps the shrub producing new healthy shoots. If a shrub is very crowded near the top, some of the smaller twiggy growth can be removed by cutting them back to a main stem.
There is one exception, the hybrids of the Lemoine Mock Orange will produce more flowers and stronger canes if they are cut back annually to healthy shoots as soon as they have finished blooming. This pruning forces the plant to produce new growth which produces more blossoms the following year. It is most important to do this pruning immediately after the shrub has finished blooming in order for the shrub to produce these shoots over the remainder of the growing season.
Of course, if a shrub is very, very old, it may simply be best to completely remove it by digging it out, properly preparing the soil, and planting a young, new healthy shrub.
