Alfalfa continues to grow with warm temperatures. So, does one harvest the tall alfalfa now, or wait until a killing frost?
The best option is to wait until a killing frost and harvest while leaves are still hanging on plants. Harvesting during current warm temperatures can cause plants to use carbohydrates needed to replenish reserves and prepare for winter. If root reserves are not replenished, stands can winter kill. Also, next spring plants will be weakened as they start to grow.
Typically, agronomists recommend eight to 12 inches of regrowth and four to six weeks of regrowth before a killing frost. This allows plants to restore carbohydrates.
Across northwest Missouri, many alfalfa fields have been harvested lately. If we only get three to six inches of regrowth before a killing frost, we will thin alfalfa stands.
For more information, contact Wayne Flanary, Regional Agronomist, University of Missouri Extension, at 660-446-3724.