Rye is not grown in a large area, mainly in the south and east of the UK and accounts for about 30,000 hectares. Winter rye grows during any warmer days of the winter, when sunlight temporarily warms the plant above freezing. It can be used to prevent the growth of winter-hardy weeds, and can either be harvested as a bonus crop, or tilled directly into the ground in spring to provide more organic matter for the next summer's crop.