When is pruning trees a good time of the year?

Keep in mind that with the exception of pruning out damaged branches to prevent further damage, no tree pruning ever benefits the tree! Even fruit tree pruning is for the purpose of developing a better crop of fruit and other reasons may include shade, or the tree is too big! Most tree surgery only ever benefits us, humans!

So it’s our job as trained tree surgeons to minimise damage caused when pruning trees so the tree or trees have the best and optimal chance of recovery. So what happens to the tree inside and is unseen when tree pruning and removing side branches for example?

If the branch is removed too close the trunk, commonly known as a flush cut, you get a greater extent of die-back internally as seen above. This is obviously poor workmanship and flush cutting should always be avoided when pruning trees. You can see how extensive columns of decay might develop in trees, with several flush cuts in similar places on opposite sides of the trunk, for example, are undertaken. 

Pruning to the branch collar enables a tree to effectively wall of decay when branches are removed. You can see in the picture above that only a small cone of die-back (black hatched area) typically develops in healthy trees when pruned correctly!

Deciduous trees

Deciduous trees (trees that lose their leaves in winter) can be pruned at most times during a growing season. As a general guide, its best avoid pruning trees when leaves are forming or falling, or in extreme frozen conditions. In some cases, for example with magnolias and walnuts, pruning is best done in late summer, as healing is quicker. 

Trees such as Prunus sp, which are prone to silver leaf disease are best pruned from April to July when the disease spores are not in the wind, and the tree sap is rising rather than falling.

Some trees can bleed sap if pruned in late winter and early spring. Although seldom fatal, this is unsightly and can weaken the tree. Birches and walnuts often bleed if pruned at the wrong time. Summer pruning can be useful to check over-vigorous growth, for example in suckering species of Populus, or restricted forms of fruit such as espalier apples. This pruning is generally light and is carried out late enough not to promote new growth.

Similarly, healthy trees will generally tolerate pruning during the summer months when trees are at their highest photosynthetic period, producing the highest amount of sugars and energy for new growth and sealing wounds.

Evergreen trees

Similarly, healthy trees will generally tolerate pruning during the summer months when trees are in their highest photosynthetic period, producing the highest amount of sugars and energy for new growth and sealing wounds. Ideally, you should also avoid pruning evergreen trees or in extreme frozen conditions.

How to prune trees

Prior to undertaking any work, it is essential you determine the tree protection status of your trees. You can read our Tree Preservation Order (TPO) information which includes trees in a Conservation Areas. If either is the case, seek permission from your local council before beginning work. Potentially dangerous limbs can, in theory, be removed without permission but the penalties for breaching the legislations, inadvertently or not, can be severe. The burden of proof will be in your hands if you underake work to a preotected tree to negate a risk, so make sure you take lots of pictures to back up your reasons for by-passing the planning process!   

Undertaking tree work

If you are choosing to undertake the work yourself, safety is of prime importance when undertaking tree surgery, so make an honest assessment of your capabilities, assess the area in which any branches may fall, and erect warning signs or barricades if necessary before beginning. If in any doubt you may call us, we provide free quotations for tree surgery services, hedge cutting and stump removal in the Southampton, Hampshire area.  

How to remove tree branches and limbs

  • Wear protective gloves and, if necessary, eye and head protection, if you are using a chainsaw make sure you are competent and have the necessary PPE!
  • When cutting a stem, cut just above a healthy bud, a pair of buds or side shoot. Where possible, cut to an outward-facing bud or branch to avoid congestion and rubbing of branches
  • Make your cut 0.5cm (¼in) above the bud. Beware cutting too close, as this can induce death of the bud. Beware cutting too far from the bud, as this can result in dieback of the stub, and entry of diseases and other infections.
  • When removing larger limbs, make an undercut first about 20-30cm (8in-1ft) from the trunk, and follow this with an overcut. This will prevent the bark tearing, leaving a clean stub when the branch is severed
  • Then remove the stub, first making a small undercut just outside the branch collar (the slight swelling where the branch joins the trunk), followed by an overcut to meet the undercut, angling the cut away from the trunk
  • Avoid cutting flush to the trunk as the collar is the tree’s natural protective zone where sealing of wounds takes place
  • There is no need to use wound paints, as they are not thought to contribute to healing or prevent disease.

If pruning cuts bleed sap, don’t bandage or bind the cut, as attempts to stem the bleeding are likely to be unsuccessful and may impede rather than aid healing.


Remove branches of more than 2cm (½in) in diameter with a sharp pruning saw. Don't make a flush cut - come out just slightly so that it heals naturally.


Apart from the problem with sap bleeding from the pruning cuts, silver leaf and coral spot, there are few other problems to contend with. But remember, no FLUSH cuts! And if you decide the works are beyond your capabilities call DGS Trees to arrange a free no obligation quote for any tree pruning or other tree surgery, hedge cutting or stump removal work.

Mark Hines Managing Director
DGS Trees