Recent research and development has investigated the factors influencing apple tree growth, with the ultimate aim of helping apple growers provide the market with fruit which is consistent in quality and which exhibits the features that consumers value, such as firmness, juiciness, colour and appropriate sugar–acid balance. This chapter offers a detailed review of how different interventions after planting allow the manipulation of apple tree growth and development. It then provides discussion of two case studies which show the importance of this factor, and illustrates how it can interact with choice of rootstock and planting system to optimize yield.