Cultivated oat (Avena sativa L.) is an old crop thought to have been domesticated over 3,000 years ago, while growing as a weed in wheat and barley fields. Oat has a low carbon footprint, substantial health benefits and the potential to replace animal-based food products. However, lack of genome resources has prevented the application modern methods of plant breeding. An international research team now presents a high-quality reference genome of A. sativa and its most closely related wild relatives.