Barley was among the first plants domesticated by humans, its origins traced to the fertile crescent of the Middle East where it has been grown for grain and fermented into beer since at least 8000 BCE. As a modern crop it is cultivated worldwide, from the Canadian prairies to the highlands of Ethiopia. In the home garden, though, its role is typically more utilitarian than culinary. Sown in fall, barley grows through winter as a cover crop, its dense root system holding soil against erosion and its leafy top growth shading out weeds with an efficiency that few other cover crops match.

Barley is not a legume and does not fix nitrogen, but the root and shoot biomass it contributes when turned in at season's end is meaningful in terms of organic matter. It is particularly useful before a wheat planting because it does not host the Hessian fly. For those who want both nitrogen fixation and weed suppression in a single sowing, barley pairs well with crimson clover. It grows in full sun across a wide range of soil types as long as drainage is adequate, and it has no serious pest or disease problems in most gardens beyond susceptibility to southern root knot nematode.