Pollarding and coppicing are bad words to most American arborists. These extreme pruning techniques are considered to be synonymous with topping. Yet, both have been around for centuries, and have actually kept some trees alive and productive significantly longer than they would naturally live.
Rather than redundantly explaining what pollarding and coppicing are, and why they are useful arboricultural techniques, I will provide this link to an article I wrote about them earlier: https://tonytomeo.wordpress.com/2018/02/12/pollarding-and-coppicing-pruning-techniques/
I am one of the rare American arborists who not only condone pollarding and coppicing, but I also use these techniques when necessary. I will be coppicing red twig dogwood soon so that it produces more vigorous red twigs next year, and also because we can not allow it to grow wild as a thicket. Some of my fig trees will get pollarded to make vigorous shoots for cuttings, and also to keep them contained in their minimal space. Both techniques are very effective if done properly.
I must stress the word ‘properly’.
Improperly executed pollarding or coppicing really is disfiguring, and can be disastrous. Yet, it is done quite often by those who get payed to maintain landscapes!
The picture above illustrates a remarkably well pollarded flowering pear tree. It was obviously done by an arborist who knows how to pollard in the English style. Although it is difficult to see in the picture, the knuckles were pruned back cleanly last year, leaving no stubble. The vigorous secondary shoots developed mostly from the knuckles, with only a few stems emerging from lower on the main limbs. When this tree gets pollarded again (and it may have already been pollarded since this picture was taken last week), it should get pruned back to the same knuckles.
The pictures below show some sort of magnolia that was severely disfigured by maintenance ‘gardeners’, probably for no other reason than it was within their reach. A magnolia can not bloom if all of the stems from the previous year get pruned off by pollarding. This magnolia happened to bloom with a few distorted flowers only because the pollarding was so poorly done, that long stubs remain. These flowers are really nothing to look at within the context of all this unsightly disfigured stems. The long stubs can not be compartmentalized as the new growth develops in spring, so will remain as open and decaying wounds as the tree matures.
So, what is the point of this magnolias even being in the landscape? It contribute nothing. It can not bloom. It can not grow into a tree, but is unappealing as shrubbery. It will always be disfigured. The disfigurement will eventually compromise its health. It would be best if it were merely removed, or at least coppiced and allowed to regenerate. Even if it is a grafted tree, and gets coppiced below the graft, the resulting growth would be an improvement, and might actually bloom if the ‘gardeners’ do not ruing it again.