Pruning Philadelphus (mock orange)

Philadelphus are glorious shrubs with exquisite fragrance. At the moment, many of them are in flower in the UK. But how should they be pruned to maintain the flower and fragrance year after year?

Most books will mention pruning after flowering. That is correct as Philadelphus belongs to the early flowering group of shrubs that flower on growth made in the previous growing season. Merely going round the shrub giving it a gentle clip with secateurs is not going to achieve anything apart from creating an inbalance between old and new wood and lead to congested unproductive growth. Unfortunately the type of gardener-often the so-called 'professional' who uses a hedge trimmer rather than secateurs to prune plants is achieving exactly that. Keep the hedge trimmer for hedges and prune with the right tools. 

Immediately after flowering, as with all shrubs remove all congested, diseased and damaged growth. Young shrubs will not need the removal of old stems  but as the plant becomes more mature, older stems will need removal at the base of the plant to be replaced by younger, more vigorous growth. In mature plants, I like to take out about a fifth of the older stems. Use a pair of loppers rather than risk twisting the blades of your secateurs if the stems are too thick (they usually are). 

Finally take your secateurs and remove flowering shoots at the point where they join non-flowering growth. Make your cuts neat and avoid leaving a 'stub' of the old shoot. If you prune well, the plant will not look as though it has been savaged with the secateurs. 

Philadelphus 'Belle Etoile' producing masses of strongly fragrant flowers