Crown thinning is a pruning technique primarily used on hardwood trees.

It is the selective removal of stems and branches to increase light penetration and air movement throughout the crown of a tree, the intent is to improve a tree’s structure.


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

The included bark forms a bark wedge when two stems grow at sharp angles to one another.

These ingrown wedges prevent strong attachment of stems often causing a crack at the point below where the branches meet. Removing one or more of the stems will allow the other stems to take over.


Crown Thinning Branches

Branches growing off these stems should 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 are removed to avoid unnecessary stress and prevent excessive production of epicormic shoots, no more than one-quarter of the living crown should be removed at a time.

If it is necessary to remove more, it should be done over successive years. Crown thinning is not suitable for all trees again as with reduction work it can create problems if carried out on some tree species.


Norfolk Trees was established in 2002 by Ashley Barnes, we operate throughout Norfolk and East Anglia. Our tree surgeons are all fully qualified for the work which they undertake and have over years experience in all aspects of tree care, which include dismantling, felling, crown lifting and 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.


Our staff allow clients to be confident and assured of the quality of our work and a £10,000,000 public liability insurance offers peace of mind. All work is carried out to BS3998 2010. In addition to domestic work we undertake commercial work for Local Authorities, Parish Councils and contract to the Borough Council of Kings Lynn and West Norfolk, Breckland Council and Serco, South Norfolk Council, Broadland Council, NCC Highways, KierMG and Anglian Water along with numerous other clients.


We are also approved by the Arboricultural Association and Norfolk County Council and are CHAS Accredited

Contractors Health & Safety Assessment Scheme.