As we start September, it’s time to decide when to take your last cutting of alfalfa.

How risky is it to harvest alfalfa during winterizing? Photo courtesy of Troy Walz.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. Your last harvest can occur anytime before winterizing begins or after the winterizing period is over with little worry about affecting stand life. But, harvest during winterizing can be risky.

How risky is it to harvest alfalfa during winterizing? Well, that depends on how much total stress your alfalfa experienced this year. The most important factor is the number of cuts you took this year. Fields cut 4 or 5 times are more susceptible to winter injury than fields cut 3 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. Stock cow and grinding hay, though, is quite plentiful and is dropping in value this year. When this hay is plentiful and reasonably priced, it may be better to purchase extra hay rather than risk another cutting. Remember, you can cut or graze after winterizing with less risk.

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

Source:  Bruce Anderson, NE Extension Forage Specialist
Photo: Troy Walz