The shape of a plant determines it's potential productivity. For example, leaf shape defines the plant's ability to capture light and produce sugars, which are used to build other parts of the plant such as the grain in grass crops like barley. Organ growth occurs over a huge scale, for example the barley leaf starts as 100s of cells and <0.1mm in size and grows to >30cm with 1000s of cells. To breed grass crops with an optional shape for different environments, we need to understand how a grass organ is patterned, how it grows over time and how it changes in response to external signals. If we can optimise crop shape to enhance potential yield, this will have implications in future breeding programs and sustainable food production. To understand how grasses grow we use a diverse combination of techniques, including genetics, molecular biology, 3D imaging and computational modelling. This allows us to build up an understanding of grass development from the gene level to the whole plant level.