Azalea flowers from the cover of Satsuki Azaleas for Bonsai & Azalea Entusiasts.
Satsuki shears are used to shape azaleas after the spring bloom and before the new buds set in the late summer/early fall. Not only does this technique keep azaleas in shape, it can also increase next years flower crop (be careful though, sometimes too many flowers can stress a bonsai – see below). All three drawings in this post are from Bonsai Today issue 1.
Thinning overly vigorous and dense growth. This helps open up the tree and forces energy into weaker zones. In this illustration the thinning is done in the fall after next years’ flower buds have set.
Satsuki shears are used here to thin individual shoots. Azaleas that are shaped but not thinned tend to become dense and may even flower more than is healthy (flowers require extra energy and trees in pots can become stressed if too many flowers make too much demand on their roots and overall metabolism).