Updated: Apr 1, 2019
Topping is the practice of cutting off the top of the tree (the crown) using horizontal cuts, thereby reducing the tree’s remaining top branches to stumps. This is not a viable method of reducing the height of a tree as it is left with weak and unstable limbs and an unnatural bare appearance. It will also leave the tree much more prone to breaking and therefore may be a risk hazard. It will also make it look ugly as it destroys the natural form of the tree. In fact, topping is the most harmful tree pruning practice known.
Lopping is the practice of removing large side branches using vertical cuts, and as this will cause the tree to grow new limbs too quickly, they will be weak and may not stand up to storms. Also this can make the tree more susceptible to disease as the cut branches are like open wounds.
Both the terms topping and lopping refer to crude or heavy-handed pruning. These methods stress your tree and so can affect its health – also, lots of leaves get removed in the process and these contain some of the tree's source of food.
In common with all reputable arborists, we do not lop or top as these techniques do not work (we leave these methods to the cowboys!) They increase the production of poorly attached endomorphic growths making the crown very dense and increasing the overall size of the crown. These practices always harm the tree and either kill the tree or make it so unsafe that felling is required. There are exceptions - for example, conifers to be used for hedging. The best way of reducing the size of your tree is to prune it correctly which will also help keep it healthy.
One method that we prefer to use is pollard pruning. This procedure trims the tree (or shrub) in a manner that will control its size and form it into an attractive, uniform shape and promote thicker foliage. We use this technique where trees cannot be allowed to grow to their normal full size, either due to the lack of space in the area in which they are growing or other restrictions, e.g. other trees, fences, overhead power lines etc. nearby. Basically, pollarding involves cutting back the top of the central leader of the tree (the vertical stem at the top of the trunk) and the side branches to roughly the same height. Large knuckles will form from which the new growth will appear and the tree ‘heals’ well with these. (Topping on the other hand doesn’t produce these knuckles and the tree is left with a large wound that does not heal well, if at all – and could lead to the death of the tree.)
The best time of year to do pollarding is towards the end of winter or in the early spring, i.e. January through to March when the tree is dormant, and thereafter should be carried out every year in order for the tree to retain its size and attractive shape. Pollarding is much kinder to the young trees, improves their look and encourages regrowth, as opposed to topping which damages the tree, can make it look pretty ugly, as well as inhibiting its regrowth. (Just out of interest, it looks like pollard pruning was used as far back as the ancient Roman times, and the Romans were very good at inventing effective ways to do things.)
Some trees may not be suitable for pollarding, but do feel free to give us a call on 020 3897 8422 if you would like to have a chat about the best way to prune your particular tree – we are always happy to advise on tree pruning methods.
Written by Leslie Chetland
6th March 2019