Secale cereale. Fall Rye is a soil builder. This cereal grain grows quickly in the fall and survives winter weather even in zone 3. It bursts into growth in the spring so try to turn under or cut back before it reaches 30cm (12"). It is harder to turn under when it is 1m (3') tall. Extensive roots loosen topsoil and improve drainage. Plant Fall Rye cover crop seeds in mid September for best results, but fall rye will germinate as late as early November. Use 50kg (110 lb) per acre.