Cell wall biosynthesis, and remodelling, is a prerequisite for plant growth; from cell plate formation in dividing cells, to the strengthening of the vascular tissue by secondary cell wall deposits. Many plant hormones are also essential for plant growth and development, such as auxin that controls cell proliferation and differentiation. Direct links between hormone actions and changes in cell wall structure have therefore been assumed, and long sought. While many studies during recent decades have supported such relationships, the vast majority have been inferred through indirect means. In an era that embraces cell-wall-related products, including cellulosic biofuels, we attempt to give an overview of phytohormone-mediated cell expansion, and cell wall biosynthesis in Arabidopsis during seedling growth.