Determining the age of branches or shoots should be done before you start directing the growth of your trees. This is because your trees will react differently to cutting or pruning of one year old growth compared to a similar cut is made into two or three year old growth. The age of shoots of most broadleaf deciduous trees can be determined by locating the rings of bud scale scars that mark the separation between one years growth and that of the previous year. As your tree gets ready for winter and dormancy it forms tough scales over the growing points or buds to protect them from the inclement winter weather. In the spring when the tree starts to grow once more, the scales covering the buds fall from the tree leaving a ring of scars marking where the bud was located. The first picture shows a set of rings on a pear tree between this years and last years growth in late May. The growth of this years shoot is still very green while last years growth has a brown color. The bud scars and bark color should both be used to locate the point of separation between one years growth and the next because the bud scale scars and not very clear on some species.
The second picture is also from a pear tree taken in late September after harvest and while the tree is preparing for winter. The bud scales are visible as is the difference in bark color from one year to the next.