Leaf growth occurs under high internal pressure – the so-called turgor pressure, which can reach several atmospheres inside the leaf cell membrane. Cell expansion, driven by this force, is the process through which the leaf grows in area by many orders of magnitude, after cell division had stopped. The process through which a leaf can grow while maintaining a specific spatial geometry is not fully understood. Leaves, being thin sheets and almost two-dimensional organs, make the study of growth simpler, with a geometry that is closely linked to the stress fields applied. This talk will focus on the role of forces in leaf growth, the dynamics of growth under external mechanical stress, as well as the mechanical properties of living leaf tissue.