There are many different techniques when it comes to pruning trees, but none of them produce quite such dramatic results as a full pollarding. Pollarding is a drastic step, taken when the maximum growth height of a tree needs to be reduced, and the large amount of the foliage removed during pollarding can put your tree's health under considerable strain. As such, it's important to know if a tree is suitable or unsuitable for pollarding and how to achieve the operation successfully without causing permanent damage to your tree.

What is pollarding?

When a tree is pollarded, its entire crown (the mass of smaller branches and leaves that makes up the bulk of the volume of a tree) is removed, with just a bare trunk and several of the largest, thickest branches left standing. This savage curtailing of the tree's growth provokes a dramatic response in certain species, resulting in the tree sprouting masses of thin, flexible young branches instead of the thick growth it would produce naturally.

The main advantage of pollarding is that it permanently reduces the size of tree, so it is often performed on urban or garden trees that are in danger of interfering with buildings or overhead power lines. However, pollarding can have other advantages too -- the young branches produced when pollarding certain tree species, such as willows, are highly strong and flexible. These branches (often known as 'withies') are long and slender and are prized for use in weaving and thatched roofs. They can also be used as a natural, biodegradable alternative to gardening twine.

Pollarding may also become necessary if a tree has extensive amounts of fragile old growth that are causing it to become top heavy. Removing brittle old growth and provoking new growth also allows the tree to devote more energy to leaf and blossom production, often resulting in thicker and more attractive foliage. 

What kind of tree species are suitable for pollarding?

To list every species of tree suitable for pollarding here would take far too long, but as a general rule, any tree with rapid regrowth rates and suitably high resistance to damage can be pollarded. Eucalyptus trees generally take well to pollarding, as do other common urban trees included beeches, oaks, and the aforementioned willows.

You should also try to pollard a tree at a young age, after it has had time to grow adult branches but before old, fragile growth starts to appear. Younger trees are also more resistant to diseases they may contract from the open wounds left by pollarding. Pollarding should generally be carried out in the winter months when less of the tree's energy is stored in its leaves and branches, as this will reduce overall damage to the tree.

How should I go about pollarding a tree?

If you are intending to pollard a small garden tree that does not entail working at heights, the job can be done yourself with standard pruning shears. However, pruning a tree of significant size is a difficult and dangerous task, requiring professional equipment and skill, so you're much better off engaging the services of a reputable tree surgery firm. Make sure to warn the surgeons of any previous bouts of disease or fungal growth that you know the tree has suffered, as these can cause hidden damage and weakening.

Once a tree has been successfully pollarded, the juvenile branches that grow back will need to be pruned periodically to prevent them growing into full sized branches. These branches can be used as the aforementioned withies if they come from a suitable species, and they also make excellent firewood.

For more information and professional assistance, contact a tree lopping and maintenance company.