Avoiding the Dangers of Tree Lopping

One of ArbWest’s members, Lindsay Lester, Top Notch Tree Surgeons, shares his insights.

There’s a clear distinction between professional, trade-certified arborists and unqualified backyard operators. ArbWest membership sets apart those who meet industry standards from unqualified tree loppers.

Perth is already facing challenges with tree canopy retention, and the rise of unqualified operators is making it worse. These so-called “cowboys” often lack even the most basic understanding of proper tree care, leading to long-term damage to our urban forest.

Three Golden Rules of Proper Tree Pruning 

The Australian Standard for Amenity Tree Pruning (AS 4373-2007) outlines key principles for maintaining tree health and safety:

1. No lopping – Indiscriminate cutting weakens regrowth, causes decay, and leads to structural instability.

2. No topping trees – Removing the upper crown reduces a tree’s ability to photosynthesize, weakens its structure, and increases stress.

3. No cutting roots without proper assessment – Tree roots provide stability and nutrients. Cutting them without expert evaluation can lead to failure, disease, and decline.

Why Topping and Lopping Are Harmful

A tree’s canopy plays a crucial role in photosynthesis, converting sunlight into energy. Removing too much foliage weakens the tree, making it more vulnerable. Best practices recommend canopy reduction should not exceed 10% (depending on species, time of year, and tree health).

When trees are topped or lopped incorrectly, problems arise:

• Weak regrowth (epicormic shoots) – These shoots grow rapidly under stress but lack structural integrity.

• Higher risk of pests and disease – Improper cuts create large wounds, allowing decay, fungi, and insects to enter.

• Water accumulation and rot – Poor pruning techniques cause water to pool, accelerating decay.

• Loss of natural form and stability – Proper pruning preserves a tree’s shape and structure, while poor practices leave them misshapen and hazardous.

The Value of Professional Arborists

Certified arborists follow industry standards, ensuring trees are pruned correctly to promote health, longevity, and safety. Proper techniques, such as collar cuts at the branch bark ridge, encourage natural healing and reduce decay risk.

Unqualified operators not only harm trees but also lower industry standards by underquoting jobs and delivering low-quality work. This devalues skilled arborists and leads to long-term costs when trees require corrective pruning or removal.

Educating the Public: A Responsibility of Arborists

Qualified arborists have a role in educating the community about proper tree care. Many property owners aren’t aware of the long-term impact of poor pruning. By sharing knowledge on best practices and industry standards, we help people make informed decisions about tree management.

Hiring a qualified arborist ensures expert care, benefiting both the environment and property values. Choosing businesses with ArbWest membership guarantees professional standards and sustainable tree management.

Written by Lindsay Lester (Director/Consulting Arborist, Top Notch Tree Surgeons (Boorn Wirin) - pictured below and above in the tree - Top Notch team pictured left