Crow reduction is about reducing a tree crown. The specialist shortens both side branches and the tip of the tree, giving the trunk spherical or elliptical shape. The accurately conducted treatment, according to Irish law, allows the tree crown to be cut down to 25 % by weight of assimilation apparatus. ( The Act of 18th of August 2011 about the amendment to the Nature Conservation Act and certain laws).

The operation influences a tree tripod, diminishes the center of gravity ( this way the risk of a tree falling, while heavy winds, is reduced), augment the amount of light reaching the tree base.

Sunlight increase is particularly important in small gardens, where smaller plants are separated or fading because of insufficient sunlight.