Key Concerns

Timing is everything—cover crops must be terminated at just the right time at the end of their life cycle. This prevents them from a) continuing to grow after being rolled or b) going to seed and spreading. This is why, unfortunately, one can’t use the roller crimper to simply mow down a field of unruly weeds mid-summer—they’ll just spring back to life. You want to roll when the cover crop reaches anthesis—when it switches from being vegetative to reproductive. In a rye or small grain, this will occur almost uniformly through the field and you’ll notice pollen shed. In vetch or legumes, which flower at different times, the rule of thumb is to roll when between 50% and 100% of the crop is flowering. In general, best results from organic no-till are achieved in hot, dry weather conditions.