Pollard Tree Pruning Technique
Pollarding is a severe tree pruning technique that involves lopping off most of a tree’s branches where they meet the trunk. Although the method is used on both young and mature trees, it differs from the coppicing pruning technique in that the tree is allowed to form a trunk and reach at least 6 feet tall before pollarding begins. Coppicing, on the other hand, requires cutting a tree or shrub all the way to the ground each year.
Cutting off a tree’s branches right next to the main trunk is the way pollarding begins. The following year, new growth is cut just above the previous cuts. Sometimes gardeners leave three or five longer branches on the tree, cutting them back each year, too, so twiggy growth erupts from the cut ends. These branches provide more shade than the shorter branches. Over time, the tree develops knobs or knuckles where it was repeatedly pollarded, and the new branches grow from only those knobs. It’s important not to cut into the knobs when pruning, and don’t cover the tree’s cuts with wax or a commercial tree-wound product. A tree heals faster if the cuts are exposed to air. Clean pruning tools with rubbing alcohol between cuts to avoid spreading plant diseases.
Pollarding is done annually or every other year and needs to start when a tree is still young, once it has reached the desired height. When a tree is pollarded, the technique needs to be continued throughout the tree's life because pollarding produces weak growth. Do your pollarding in late winter or very early spring, when the tree is dormant. The worst time to pollard is in fall because fungus is more apt to enter the cuts then.
Deciduous trees and large shrubs respond best to pollarding. The tulip tree (Liriodendron tulipifera), which is hardy in U.S. Department of Agriculture plant hardiness zones 4 through 9, typically reaches 60 to 90 feet tall, much too large for most urban lots. It can be kept more manageable by pollarding. The horse chestnut (Aesculus hippocastanum) is another commonly pollarded tree. It reaches 50 to 75 feet and is hardy in USDA zones 3 through 8.
History and Uses
Historically, Europeans pollarded and coppiced trees to produce quick wood growth for kindling, fencing and basket-making. Nowadays, pollarding keeps tree branches from interfering with electrical wires and obstructing pedestrian and vehicular traffic. It is also used to keep large trees smaller than normal and reduce the shade they cast. The new growth on some trees is colorful, with pollarding producing constantly fresh branches.
Pollarding a tree is labor-intensive and, once the tree is mature, often requires the services of an arborist. If the tree’s knobs are damaged in the process of pollarding, then the tree will react as though it has been topped – sending up a forest of spindly, vertically growing water sprouts. Instead of planning to pollard a large tree, consider planting a tree that will fit the space and require only light pruning. Some people consider a knobby, pollarded tree to be ugly and unnatural-looking.
- Horticulture: Pruning Techniques -- Coppicing and Pollarding Trees and Shrubs
- Royal Horticultural Society: Pollarding
- New Mexico State University Cooperative Extension Service: Tree Pruning Techniques
- University of Florida IFAS Extension: Developing a Preventive Pruning Program in Your Community -- Mature Trees
- Missouri Botanical Garden: Liriodendron Tulipifera
- Missouri Botanical Garden: Aesculus Hippocastanum
- Jupiterimages/Photos.com/Getty Images