Trees were pollarded for livestock fodder or wood. Fodder pollards produced "pollard hay", being pruned at intervals of two to six years so their leafy material would be most abundant. Pollarding was preferred over coppicing in wood-pastures and other grazed areas, because animals would browse the regrowth from coppice stools. Pollarding in woodland encourages underbrush growth due to increased levels of light reaching the woodland floor. This can increase species diversity.
When to prune depends on several factors, notably the species being grown and the reason you are pruning. Pruning can actually stimulate growth. Pruning back a weak branch in late winter or early spring will often cause the new growth that replaces it to grow much faster. To slow growth down, prune in early summer. These are the two basic principles of pruning, but there are numerous exceptions.
Coppicing and pollarding are two methods of wood pruning that allows us to continually harvest wood from the same trees while keeping them healthy for centuries. They produce a sustainable supply of timber for many generations while enhancing the natural state for wildlife and native plants.
.all the trees were trimmed like this when i was little.....at the cemetary across the street from my grandparents house