Managing Freeze-Damaged Alfalfa

The Easter-weekend freeze that covered much of the country did a little more than give the Easter bunny the shivers. It also put a pretty good hurt on lots of small grains and hay, including alfalfa.

According to Jim Shroyer, Kansas State University research and Extension agronomy state leader, now's a good time to take a hike through your alfalfa fields and take stock of the damage.

"Where the alfalfa is damaged by freeze, the leaves will probably turn dark, then start falling off a few days later. The plants may also collapse or fall over if the stems are injured." If you observe this in your alfalfa stands, you may want to mow or shred the plants and let them start all over again.

However, Shroyer says that may not always be necessary.

"This should only be done if the growing point clusters are frozen, the new regrowth is occurring only from the base of the plants, and the plants can be cut without damaging the new regrowth," he says.

If you're going to mow or shred, set your machinery to leave 2-3 in. of stubble to help encourage regrowth. And be aware that freeze-damaged alfalfa that is 6-8 in. tall or less will be slower to regrow after mowing and shredding than taller plants.

According to Bruce Anderson, University of Nebraska-Lincoln forage specialist, here are some things to watch for on well-established alfalfa stands:

  • New growth emerging from the tip. This means plants are recovering and no action is necessary.
  • New growth emerging as branches below the tip. This means the growing point was killed, slowing plant development significantly, but recovery is occurring. No action is needed.
  • New shoots emerging from crown buds. This means the growing point was killed and very little new growth can be expected from existing shoots. Cut or graze if sufficient growth is available for economical harvest before the new shoots get tall enough to be damaged by the harvest. Caution: cutting or damaging new regrowth shoots will cause severe, sometimes fatal, damage. If the new regworth has grown too tall to safely cut the plants, just let the new shoots develop and expect to take the first cutting much later than normal.
-- KSU Release