Crown Thinning
Thinning involves removing internal branches of the tree, reducing the density of the crown but not the overall size and shape, thus improving light penetration and air movement. Dead and diseased branches are removed first, followed by crossing / rubbing branches and secondary growth. Then if necessary other branches to achieve the desired effect. If thinned too much the tree becomes stressed and re-growth appears very quickly, which reverses the benefit of the process.