Pollarding London Plane Trees
In order to keep my working farm and all its gardens, allées, and groves as beautiful as possible, I pay lots of attention to the care and maintenance of all my trees.
The London plane, Platanus × acerifolia,is a deciduous tree. It is a cross between two sycamore species: Platanus occidentalis, the American sycamore, and Platanus orientalis, the Oriental plane. In 2019, I planted an allée of London plane trees along the carriage road in my middle hayfield. Since then, they've thrived, growing two to three feet annually. This year, I decided I wanted the trees pollarded, a pruning technique that involves the removal of a tree's upper branches to promote the growth of club-headed stems and dense new foliage. London planes are well-suited for pollarding and respond well to this practice. Last week, my gardeners took on the detailed task.
Here are some photos, enjoy.
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- The London plane is a large tree that grows up to 65 to 130 feet when fully mature. In recent years, I’ve planted London planes in my maze, outside a paddock, and here as part of a long allée in my middle field. Here is the allée in spring.
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- In landscaping, an allée, or an avenue, is traditionally a straight path or road with a line of like trees or large shrubs running along each side. To create this particular allée through my field, I started with a selection of 46 London plane trees. I also planted about 100 royal purple smoke bushes, Cotinus coggygria.
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- These London planes and the smoke bushes below them have thrived here, growing multiple feet every year. The London plane is one of the most efficient trees in removing small particulate pollutants in urban areas. In fact, it was planted extensively in Victorian times to weather the pollution of London.
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- The leaves of the London plane are thick and stiff-textured, broad, palmately lobed, and maple-like.
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- This year, after the trees had lost all their leaves, I decided to pollard them. London planes are often pruned by pollarding. A pollarded tree creates a distinctive shape that is smaller than what would naturally grow.
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- This photo was taken just before pruning began. It was a very cloudy day with snow showers, but not too windy so it was perfect for some tree work.
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- The best time to prune and pollard trees is when the trees are dormant, during the cold months. It’s best to complete all pruning before early spring when the buds begin to form. Dormancy pruning reduces the amount of stress placed on the tree. The reduced flow of fluids in the tree during the time helps the pruning wounds heal quicker.
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- Josh starts by cutting the “Ds” of pruning – dead, diseased, damaged or deranged – those branches that rub against other branches or point the wrong way.
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- Always use sharp secateurs, loppers, or a pruning saw to make clean cuts and avoid damaging the bark. Remember, a sharp tool always cuts clean, and helps the plant to recover better. Dull cutting tools rip and shred the plant tissue.
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- After pruning all the Ds, Matt starts pollarding, which is essentially pruning to form a “knuckle” or “bole” by removing growth back to the main stem.
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- All the trees in this allée are trimmed to the same height. Pollarding is started when a tree or shrub reaches a certain desired height.
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- On this cut branch, one can see the nodes. A node is the point on a stem where leaves or buds grow. When pruning a branch, one should cut just above a node on the stem, not below it; cutting below a node leaves a section of stem that cannot grow new growth and is prone to rotting and disease.
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- Another benefit of pollarding a tree is that it creates dense shade. Cutting back the trees encourages them to send out multiple shoots.
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- The bark of a London plane is usually pale grey-green or buff-brown and exfoliating.
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- Here is a section of a tree showing the peeling habit. London plane trees shed their bark in large flakes as a natural process to cleanse themselves from accumulated pollutants. It is a way to way to shed old bark for fresh, new and developing layers.
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- This entire process takes a few days to do properly by hand, but it is all worth the efforts to have well-manicured, healthy trees. Each year the long slender shoots that grow below the cuts will be removed, and a set of new shoots will develop creating a gnarled appearance.
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- Pollarding can help make trees live longer by maintaining them in a partially juvenile state and by reducing the weight and windage of the top part of the tree.
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- Regular and thorough pruning will give the branches more air circulation and room to grow.
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- Here is one tree all done – these will look even better in about three years. More thought and planning goes into pollarding than regular topping and lopping. Pollarding is similar to coppicing but plants are cut back to a stump, rather than down to the ground.
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- And here is a section of the allée all finished. Some of the other types of trees that can benefit from pollarding include beech trees, black locust trees, catalpa trees, hornbeams, horsechestnuts, mulberry trees, redbuds, and willows. I am looking forward to seeing the dense heads of foliage on these trees come spring.
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