Not all shrubs require pruning but you may want to consider it in order to shape the plant, to encourage vigorous growth, flowering or fruit production or to remove dead, damaged or diseased material.
Here is a beginners guide to pruning:
- Pruning is best carried out immediately after flowering to ensure a good display the following year but a general pruning in Autumn is also usual particularly for roses
- Always cut at a downward angle to allow rain to fall away and not sit on the cut
- Pruning to remove spent flower heads is always a good idea as it stops the plant spending energy producing seed
- Always use good quality, sharp, clean tools
- Cut out dead or diseased stems right down to where they reach the roots or main stem
- Take out any stems that cross over other stems as they will eventually join together and cause injury which can let in disease
- Take a look at the plant and decide what size and shape you want and bear this is mind throughout the pruning process
- Take a stem and starting at the tip look along it’s length to where it reaches the base. The “nodes” you see along the length are where either leaves, new stems or flowers will appear; you won’t know in advance which of these it will be
- By pruning just before a node (i.e. before when looking from the tip to the base) you stimulate a chemical at the node which tells the plant to shoot out from there and produce a flower, leaf or another stem
- If you prune after a node the chances are that the stem will die back from the end down to the next node and may even continue down the stem
- To hard prune, count the number of nodes up the stem from the base; you should leave at least two nodes to allow for die-back so pruning just before the third node is usually ideal; this type of pruning produces new growth and reinvigorates the plant
- For an annual prune when you just want to keep the shrub in shape so you should cut just above the node needed to maintain the shape; this type of pruning usually produces flowers and new leaves the following season
Next you can find out more about pruning specific types of plants:
Evergreens – During May cut out dead, weak or crossing branches and remove extra branches if the shrub is overcrowded. Examples: Camellia, Pieris, Rhododendron –
Early Flowering Deciduous Shrubs – Immediately after flowering cut out dead, weak or crossing branches and remove extra branches if the shrub is overcrowded. Cut back all branches which have flowered this year. Examples: Forsythia, Weigela, Deutzia, Philadelphus
Later Flowering Deciduous Shrubs – During January to March before the new growth appears cut out dead, weak or crossing branches and remove extra branches if the shrub is overcrowded. Cut back all old wood to the ground. Examples: Buddleia, Hypericum, Cornus
Damaged or Diseased Trees – Identify the diseased or damaged branches and cut back to healthy, clean wood.
Clematis
Group 1 – these are small-flowered species which flower in early spring on last season’s growth Immediately after flowering remove dead or damaged stems, and reduce other stems if needed. To renovate an older plant cut back to 15-30cm (6-12in) from the base immediately after flowering
Group 2 – large-flowered, flowering May-June on the previous year’s growth. Some flower again in summer on current season’s growth. Remove dead and damaged stems in early spring before growth begins, trimming all remaining stems to a pair of strong buds. To rejuvenate a mature specimen remove old shoots during spring
Group 3 – flowers late summer on current season’s growth. Cut back all growth to a pair of strong buds 15-20cm (6-8in) above soil level, before growth begins in early spring