Tree pruning is a multifaceted endeavor that blends the art of shaping with the science of tree biology. Its a crucial aspect of arboriculture that serves to maintain a trees health, aesthetics, and safety. In this extensive guide, we will explore two significant pruning techniques: pollarding and topping. By knowing the pros and cons of each method and when it’s best to use it, you can make smart choices about how to take care of your trees.
Pollarding is a pruning technique performed on trees to control their height and growth. It involves cutting back the upper branches and crown of a tree to just above the trunk or main stems. This stimulates new growth and creates a distinct knob or knuckle at the cut site from which new branches emerge. But is this drastic pruning method actually bad for trees?
Understanding Pollarding
Pollarding has been practiced for centuries, originally as a way to harvest wood and encourage dense regrowth for livestock fodder. Today, it is commonly used in urban areas to contain large trees within limited overhead space.
The pollarding process typically begins when a tree is young, cutting it back to just above the main stem to encourage new branching. After the initial pruning, pollarding is performed periodically generally every 1-3 years for smaller trees and every 2-5 years for larger trees. The regrowth is cut back to the previous knuckle each time.
Pollarding is only suitable for certain deciduous tree species that readily re-sprout after pruning, such as:
- Oak
- Maple
- Ash
- Beech
- Linden
- Mulberry
Attempting to pollard trees unsuited to the practice like conifers, can harm or kill the tree.
Potential Drawbacks of Pollarding
When done incorrectly or on unsuitable trees pollarding can have some drawbacks
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Stress: Drastic pruning and regrowth cycles may stress the tree over time if not allowed adequate recovery periods between pollarding.
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Disease vulnerability: The bare knuckles left after pollarding are vulnerable points of entry for pests and diseases.
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Appearance: Some may consider the gnarled knuckles unsightly. The tree also loses its natural form.
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Branch failure: New sprouts after pollarding may have weak attachments that are prone to breaking.
Benefits When Done Correctly
However, when performed properly by trained arborists on appropriate tree species, pollarding provides many benefits:
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Height control: Contains large trees to fit urban spaces.
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Safety: Removes heavy top growth that could pose hazards if left in place.
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Longevity: Cyclical pruning can extend a tree’s lifespan.
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Density: Stimulates dense foliage regrowth.
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Youthful vigor: Promotes juvenile growth, maintaining a tree’s vitality.
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Historic method: Preserves traditional pollarding practices.
So pollarding itself is not inherently bad if applied correctly. In fact, it can be advantageous for certain management goals.
Best Practices for Healthy Pollarding
The key is proper technique and timing when pollarding trees:
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Select appropriate tree species that tolerate radical pruning.
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Start pollarding when trees are young to preempt large wounds.
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Make cuts just outside branch collars to avoid damaging stems.
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Time cuts in winter during dormancy to minimize stress.
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Allow adequate years between subsequent pollarding for regrowth.
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Monitor for defects like cracks that indicate the tree is declining.
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Be prepared to discontinue pollarding if the tree shows signs of failure to thrive.
Consult Arborists for Proper Pollarding
Pollarding is a specialized technique that requires expertise to implement successfully. Before pollarding trees on your property, consult with professional arborists. They can assess your trees’ health, appropriateness for pollarding, and recommend proper timing and methods. With knowledgeable guidance, pollarding can be executed in a way that sustains, not harms, your trees’ vigor.
Historical Roots and Modern Use
The technique of pollarding has deep historical roots dating back centuries to Europe. Traditionally, it was used to produce a substantial quantity of small-diameter branches from a consistent source. Farmers could always feed their animals, start fires, and make baskets, fences, and other structures by cutting back the branches every year and harvesting the long, thin watersprouts.
In contemporary urban landscapes, pollarded trees are a common sight. The technique is employed to maintain street trees in confined spaces. Instead of letting a tree grow to its full size, which could damage buildings and power lines, pollarding can keep a tree healthy at a much smaller, easier-to-manage size.
Why Topping is Discouraged
Topping a tree can have several unfavorable consequences:
- Less energy production: topping makes it harder for trees to make energy through photosynthesis. It throws off the ratio of roots to crowns, which upsets the balance of making and storing carbohydrates. The trees usually die when they lose a lot of their photosynthetic potential and their stored energy quickly.
- Disease is more likely to spread because cutting off large parts of a tree’s crown usually means making cuts that are too deep for the tree to heal properly. Because the tree can’t separate the wound, it’s open to decay, fungal infections, and insect infestations, all of which can kill it in the end.
- Watersprout Growth: If a tree makes it through topping, it usually responds by making watersprouts. Watersprouts are buds that are dormant until they are activated. They then grow quickly and randomly, usually up and down. This growth pattern defeats the purpose of the initial topping cut and, because the attachment is weak, there is a chance that the branch will break.
How Not to Pollard a Tree
FAQ
What are the disadvantages of pollarding?
Does pollarding hurt trees?
What trees are good for pollarding?
What are the benefits of Pollard trees?
Can a tree be pollarded?
Not all trees are suitable for pollarding and it would be a tree pruning mistake to try this technique without researching beforehand. There are many trees that can be pollarded and it is deciduous, broadleaf trees that regrow rapidly that are best. Such examples include oak, willow, beech, eucalyptus, mulberries, ash and lime trees.
How does pollarding affect trees?
Understanding the impact of pollarding on trees is essential for anyone considering this method for managing their green assets. At its core, pollarding is a form of tree pruning that is initiated when a tree is young. The process involves cutting back the tree’s branches to the trunk, from which new shoots emerge.
Does pollarding kill trees?
Pollarding, when performed correctly, typically does not kill a tree. When done improperly, such as cutting too much of the tree, it can lead to stress and potential decline, but when executed with care, it can benefit certain tree species by promoting new growth and extending their lifespan. Is pollarding bad for trees?
Is Pollarding a bad practice?
Young trees are less prone to disease and they regrow faster than the older ones. As for many, pollarding is a bad practice. And to shun this notion, the bad practice for trimming trees refers to topping, not pollarding. Topping is the method where the top section of the tree or central trunk is cut, and it’s performed commonly to old trees.
Is pollarding good for trees?
By regularly removing the upper branches, the tree’s wind resistance is decreased, making it less likely to be uprooted or damaged during high winds. This aspect of pollarding not only protects the tree but also the surrounding property and individuals. Despite its benefits, pollarding is not suitable for all trees.