Winter or Frost Kill
Some cover crop species will winter or frost kill. Winter cover crops that can winterkill include black oats, oats, radishes, and some other brassicas. None of these cover crops reliably winterkill in the Coastal Plain. This can present a dilemma when brassicas are included in cover crop mixtures before late planted crops like cotton. The brassicas will tend to flower and set seeds before the optimal termination dates for the rest of the cover crop mixture.
Most summer cover crops will frost kill. These includes buckwheat, cowpeas, millets, sudangrass sorghum hybrids, sunflowers, and sunn hemp. The summer cover crops planted after corn can be allowed to frost kill. The residue can have a winter cover crop planted into it or be left for planting the early spring cash crop.
More Information:
- A Simple Guide for Conservation Systems in the Southeast. USDA ARS
- Termination of Cover Crops: Management Considerations for the Subsequent Cash Crop. Conservation Systems Fact Sheet No. 11. USDA ARS
Contributors:
Dr. Charlie Cahoon, Extension Specialist, Virginia Tech; Dr. Stanley Culpepper, Extension Specialist, University of Georgia; Dr. Mike Flessner, Extension Specialist, Virginia Tech; Julia Gaskin, Extension Specialist, University of Georgia; Dr. Erin Haramoto, Assistant Professor, University of Kentucky; Dr. Andy Price, USDA Agricultural Research Service; Dr. Mark Reiter, Extension Specialist, Virginia Tech; Dr. William Vencill, Professor, University of Georgia