Before reaching for the pruning tools you need a clear idea of what you are hoping to achieve and in the context of this post it is a healthy plant which fits both physically and aesthetically into its location in the garden. It must not overwhelm the area around it or in the end look unattractive to the eye.
Pruning is not the easiest of things to teach, partly because of the different requirements of different plants but equally because it is as much art as science. To start with a few preliminaries:
- Plants don’t always respond well to pruning – not all plants will come again if you cut into old wood, this includes nearly all the conifers but also a number of others.
- Those that do, don’t always do as you expect – often a plant will respond to pruning by producing a mass of soft shoots rather than one or two useful ones.
- Once you’ve cut it off you can’t put it back – so if in doubt delay cutting and then take off a bit at a time to see how it looks
- Think ahead to prevent accidents – you would be amazed at the number of people who actually cut off the branch they are sitting on!
- Make sure you are suitably equipped – as you will never make a tidy job using poor/blunt tools.
- Plan first, act second – have a really good look at what you’re tackling and how your cuts are going to affect the plant before you do anything.
Plants which should not be cut back into old (brown not green) wood include nearly all conifers. They resent being cut back beyond their green foliage, except for Yews which can grow away vigorously from old wood. Botanists insist Yews are conifers but try as they might, from a gardeners point of view, Yews are not very good at being conifers. Most deciduous shrubs respond well to being cutting back but more caution should be used with evergreen shrubs and it may be better to spread the work over a number of seasons. Some such as lavender is not worth trying so it’s a case of live with it or replace it.
Thought should also be given to a shrub’s value be it sentimental or otherwise. With any attempt to drastically cut back a plant there is always the chance it may not be successful so consider “what if I lose it” and moderate your actions likewise. For example on the one hand a choice tree peony which is slow and relatively unusual would receive the minimal of cutting back while on the other hand a Berberis, a very good garden plant, which is readily available and grows quickly can be cut back very hard safe in the knowledge it will probable quickly recover and if not it is easy to replace. I’ve seen Berberis cut down to ground level and recover.