Oriented cell divisions are crucial to determine the overall morphology and size of plants, but what controls the onset and duration of this process remains largely unknown. We recently identified a small molecule which activates root meristem expression of SQUAMOSA PROMOTER BINDING-LIKE13, a known player in the shoot juvenile to adult transition. This leads to oriented cell divisions in the root meristem via SHORT ROOT and cell-cycle regulators. We further show that the root meristem has distinct juvenile and adult phases typed by morphological and molecular characteristics and that SPL factors are crucially required  for this transition in Arabidopsis and rice. In summary, we provide molecular insights into the age-dependent morphological changes occurring in the root meristem during phase change. The root meristem aging research team currently consists of Veronika Jirásková and Elisa Drijvers.