Many of us know we should prune shrubs in late winter/spring for maximising flower and fruit crops, but most of us forget that certain beauties need ‘a hair cut’ in late summer that will keep their growth in check and allow plenty of time for new wood to ripen and flower the following year. Prune at the wrong time of the year and you will be cutting off this year’s flowers.
One such shrub that most people make this mistake with is Philadelphus, Mock Orange. Its highly scented flowers mean it’s often planted near the house and come springtime people look with despair at the wayward growth covering windows and obscuring pathways and give it a good old No.1 haircut, taking off all this summer’s flowers in the process! So now is the ideal time to bring this beauty back into shape.
- Cut stems about 15cm (6″) lower than the maximum that you want the shrub to flower at next year (it will put on this much growth between now and leaf fall in late autumn when it becomes dormant).
- If the shrub is well overgown then renovate prune by cutting 1/3 of the oldest stems to just above ground level. These will provide flowers much lower down the plant next year.
- Over the following 2 years you can repeat this process, whilst gently trimming the new lower growth.
- By the end of year 3 you will have the plant back to the height and shape you desire.
Evergreen shrubs such as box (Buxus), yew, lavender, rosemary and bay can all be pruned now. Box and yew can be pruned hard back into old wood if they need renovating, but all the others won’t re-leaf if you cut below the lowest leaves on a shoot. So, for rosemary, lavender and bay always leave some leaves below the point you cut. The herb cuttings can be tied together with raffia (red looks very festive) and used to add flavour on the barbecue or as fragrant firelighters over winter.