Crown Thinning

Information about crown thinning

When crown thinning may be useful

Crown thinning can be useful when a tree crown has become dense, congested or structurally poor.

It is commonly used to:

• Increase light penetration through the crown
• Improve air movement within the tree
• Remove crossing or rubbing branches
• Reduce congestion within the crown
• Improve branch structure and crown balance
• Help reduce unnecessary stress on selected limbs

Crossing branches and included bark

Crossing branches and stems with narrow, V-shaped angles of attachment should often be selected for removal first.

These tight angles can form included bark, where bark becomes trapped between two stems growing close together. This can prevent a strong attachment from forming and may lead to cracking below the point where the branches meet.

Removing one or more of the affected stems can allow the remaining branches to develop with better structure.

Crown thinning branches

Branches growing from main stems should generally be no more than one half to three-quarters of the diameter of the stem at the point of attachment.

Branches that rub or cross should be removed to avoid unnecessary stress and help prevent damage or fracture in adverse weather.

No more than one-quarter of the living crown should usually be removed at one time. If more work is required, it should normally be carried out over successive years.

When crown thinning may not be suitable

Crown thinning is not suitable for every tree. As with crown reduction, it can create problems if carried out on certain tree species or if too much material is removed at once.

Before crown thinning is carried out, the tree should be assessed carefully to decide whether thinning is the best option for its condition, species and location.

Professional crown thinning by Norfolk Trees

Norfolk Trees was established in 2002 by Ashley Barnes and operates throughout Norfolk and East Anglia. Our tree surgeons are fully qualified for the work they undertake and have experience across all aspects of tree care.

Our work includes dismantling, felling, crown lifting, crown reductions, dead wood removal, formative pruning, tree surveys to BS5837, tree hazard reports, pest and disease diagnosis, bat inspections, stump grinding or treating and tree planting.

Clients can be confident in the quality of our work. Norfolk Trees holds £10,000,000 public liability insurance and all work is carried out to BS3998:2010.

In addition to domestic tree work, we undertake commercial work for local authorities, parish councils and other organisations, including the Borough Council of King’s Lynn and West Norfolk, Breckland Council, Serco, South Norfolk Council, Broadland Council, NCC Highways, KierMG and Anglian Water, along with numerous other clients.

We are also approved by the Norfolk County Council, and are CHAS Accredited through the Contractors Health and Safety Assessment Scheme.