Planning That Last Cutting Of Alfalfa

When you take your last harvest of alfalfa affects your crops winter survival and vigor next spring. 

Alfalfa needs about six weeks of uninterrupted growth in the fall to become well winterized.  This winterterizing generally begins about three weeks before the average date of first frost, which means it's best if you last harvest falls any time prior to or after the winterizing period. Harvest during winterizing can be risky.

How risky is it to harvest alfalfa during winterizing?  Well, that depends on how much stress your alfalfa experienced this year, particularly the number of cuts you took. 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 varieties that may be only moderately winter hardy.

Also consider your need for extra alfalfa or its cash crop value.  Dairy hay still is priced high, so cutting dairy hay from this final harvest may be worth the risk of lowering next year's yield.  Note, however, that stock cow and grinding hay is quite plentiful and has dropped in value this year.  When this hay is available and reasonably priced, it may be better to purchase 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 can control the risk.

Bruce Anderson
Extension Forage Specialist