Our mild climate makes it too easy to overwinter cover crops. Then the typically wet springs (and, on our farm, wet soils) let the cover put on loads of topgrowth before getting on the soil. Buckwheat is the only crop that I can be certain will winterkill. Field peas, oats, annual rye and crimson clover have all overwintered here. Any suggestions?
Finding just the right cover crop-tillage combination for crops planted the last half of June has always been a real challenge in our location. While surface-tilling mature rye and vetch in May works well for fall crops established in July and August, this cover crop-tillage combo does not allow enough time for decomposition and moisture accumulation for end-of-June plantings.
Our cover crops have to provide the benefits of smothering weeds, improving soil structure, and replenishing organic matter. They also have to produce some income. For these purposes, we use turnips, mustard and lettuce within our plant successions. I broadcast these seeds thickly on areas where cover crops are necessary and let them do their work.