Safely Harvesting Alfalfa During the Winterizing Period
A tempting amount of alfalfa growth may be available for harvest in early fall. A careful harvest will help assure it's also available next year.
During early fall, alfalfa plants detect that the amount of sunlight each day is getting less. This tells them winter is coming so they change their growth process to prepare for winter. If you cut your alfalfa during this winterizing period, the plant will begin to regrow. This reduces its ability to winterize as fully as it would if it hadn’t been cut.
Alfalfa cut in late September or early October often survives just fine, but spring growth may be slowed. The solution may be in increasing the chance of alfalfa survival over winter with good growth next spring.
Most importantly, make sure your alfalfa gets a chance to grow well for a long time in late summer to build its root nutrient reserves. Allow at least six weeks between your previous cutting and the cut that occurs during winterization. This is especially critical if the field is cut five or more times during the year.
Second, thoughtfully select fields to be cut during winterization. Avoid old, thinning fields unless you plan to rotate the field to a different crop next year. Young, healthy alfalfa fields containing varieties with good winter survival ratings are most likely to perform well even after cutting during winterization.
Lastly, consider waiting to cut or graze until mid-October, after winterization is over or plants are nearly dormant. The stress of regrowth following this extra late harvest usually is small.