The Beginner’s Guide to Pruning & Trimming
Although this can appear to be an onerous task for many new gardeners, the good news is that pruning and trimming plants is not really all that complicated. In fact many plants don’t need any sort of pruning or trimming - so the first thing to make sure is whether it is necessary in the first place!
PRUNING WOODY PLANTS
The plants that are most likely to need pruning are those with woody branches - and this refers top-fruit trees (like apples and pears), shrubs, and roses (you can also keep larger trees at a lower height through careful pruning but it is often better to plant the right tree for the right place and make sure that it does not outgrow its space).
Then with a sharp pair of secateurs, loppers, or a pruning saw for thicker branches, the idea is to cut just above a leaf joint or back to the main stem. The first thing to do is to remove dead branches, then diseased branches, then crossing branches, and finally to neaten the overall plant once these have been removed.
As a rule of thumb I tend to remove about a fifth of the branches on any one plant each year if I’m rejuvenating an old shrub (and therefore keeping the plant strong and healthy and discouraging it from sending up a multitude of leafy shoots). For Cornus or Salix though, where you are would be pruning to encourage their stem colour, cutting stems to just above ground level every couple of years works best.
Another point to consider is when to prune a plant. Again my general thought here is that - although you can look this up for each plant individually - just after it flowers and the flowers have faded is best, as you should then get flowers the following year. For evergreen plants though mid Spring is usually a good time.
SPECIALIST PRUNING
A special mention is also reserved for roses and clematis. For shrub roses I cut them back in early spring to around 15-25cm above the ground (and I use hedge trimmers, although using secateurs is more usual). I then remove any old dead wood to encourage new shoots. With Clematis it is important to know what you have as these come in various “pruning groups” depending on when and where they flower (for example in spring or summer, or on new shoots or year-old shoots). Generally though prune back in winter, although with the larger headed, mid-summer flowering varieties (flowering on new growth) being cut back closer to the ground, as opposed to waist height pruning of varieties with an earlier flowering.
PRUNING HEDGES AND TOPIARY
Trimming of hedges and topiary generally needs to be done once or twice a year. I favour a slightly less formally angular vision for my plants generally so I’ll trim once a year (although fast growing hedging - like privet - needs pruning every couple of months in the growing season). Hedge trimmers or shears work best - providing they are sharp - with late spring or early autumn generally the best time to trim. However it is worth remembering that Box hedges are best trimmed is dull weather to prevent newly trimmed edges getting scorched by the sun.
DEADHEADING PLANTS AND REJUVENATING FLOWERS
Finally more delicate ‘pruning’ can be undertaken in the form dead-heading. Deadheading is the act of removing faded blooms to encourage more (ensuring that the plant does not have a chance to set seed). You don’t need to do this but it does encourage more flowers. Also a variant on this is the well-known ‘Chelsea Chop’ where floriferous perennials are cut back, usually prior to flowering and to just above the ground, at the end of May. This encourages a later (and denser) flowering on a more compact plant.
Generally though you would just remove the flowers as they fade. For single flowers these can be removed where thy join the main stem (or for roses just above the next leaf joint or next shoot); for many short-stalked clustering flowers you can do the same or if all have faded you can again trace the stalk back to the main stem and trim there. Finally spring bulbs should be deadheaded just behind the flower, leaving the stalk in place (to allow the bulb to re-absorb as many nutrients as possible).
The art of pruning and trimming is therefore just really an understanding of how the plant grows and this is a skill anyone can develop over time. It doesn’t have to be a chore, nor is it particularly complex, but it can add an extra dimension to a planting scheme over the course of a season…and usually if you make a mistake that will rectify itself over time!
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