September 13, 2013

When deciding when to take your last cutting of alfalfa, consider these points: 

The date you take your last harvest of alfalfa affects its winter survival and next spring's vigor. Alfalfa needs about six weeks of uninterrupted growth in the fall to become fully winterized. This winterterizing generally begins about three weeks before the average date of first frost, which means in much of Nebraska, this winterizing has just begun. Your last harvest can occur anytime before or after winterizing with little worry about affecting stand life. However, harvest during winterizing can be risky.

The degree of risk depends on how much stress your alfalfa experienced this year. The most important factor is the number of cuts you took this year. Fields cut four or five times are more susceptible to winter injury than fields cut three times or less. Also, young stands of winterhardy, disease-resistant varieties are less stressed and can be harvested during winterizing with less risk than older stands of disease-susceptible varieties that are only moderately winter hardy.

Also consider your need for extra alfalfa or its cash crop value. Hay is pretty expensive, so cutting this final harvest may be worth the risk of lowering next year’s yield. When this hay is plentiful and reasonably priced, it may be better to buy extra hay than risk another cutting. Remember, you can cut after winterizing with less risk.

Harvesting alfalfa during its winterizing period is risky, but by reducing total stress, you control how risky it is.

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Bruce Anderson
Extension Forage Specialist