Question: what are rhs pruning groups?
Answer: Pruning group 1: Light pruning. ...  Pruning group 2: Early-flowering shrubs. ...  Pruning group 3: Shrubs which shoot from the base. ...  Pruning group 4: Summer-flowering shrubs (Hydrangea) ...  Pruning group 5: Deciduous winter and early spring-flowering shrubs. ...  Pruning group 6: Summer or autumn-flowering shrubs.