Creative Gardens Q&A - Unhealthy Shrubs

QUESTION

Some of my shrubs are straggly and didn't flower that well last year. Should I cut them back or will that damage them?

ANSWER

If you have been disappointed by some of your shrubs that have not produced an abundance of flowers, pruning in Spring will encourage new flowering stems. Left unpruned deciduous shrubs that bear flowers on the current season’s growth tend to become congested and flower quality deteriorates.

Here are some shrubs that will benefit from spring pruning:

Abelia, Buddleia, deciduous Ceanothus, Forsythia (after flowering), Fuchsia, Spiraea,  Perovskia.

It is best to use a good sharp pair of secateurs, long handled loppers are needed for thicker stems or use shears where there is a great deal of dead weak light growth which needs to be removed.

As a general rule the best time to prune your trees and shrubs is immediately after flowering. This helps to promote good healthy growth of new stems. As well as helping to control the height of your shrubs removing any damaged or dead stems which can become diseased is important. If you are unsure which stems are dead scrape a small section of the stem or branch. If the lower layer is green then the branch is alive if the tissue is brown then it is dead and should be removed.

Prune out the stems of the previous year’s growth to within 2 – 4 buds of old wood. Always cut the stem at a 45 degree angle making a sharp clean cut just above an outward facing bud. This will encourage the new stem to grow outward and not inwards. Cut back some of the main stems to the base to retain an open framework.

Buddleia needs a more drastic prune. Using loppers cut back all the main shoots that flowered the previous year to within 1 -3 buds of the old wood. 

Evergreen shrubs such as Rhododendrons and Azaleas do not need pruning at all unless they have dead or damaged stems.

All you need to do now is add a good quality fertiliser to promote fresh healthy growth. You will almost hear your shrubs breathe a sigh of relief, glad to be rid of dead and unhealthy branches.