February 29, 2012

February’s snow storms were good for alfalfa. In fact, alfalfa just loves snow. Nothing increases the chance of alfalfa surviving winter better than a thick blanket of snow.

Our moderate fall weather allowed alfalfa plants to harden well for winter, leaving them with a high concentration of nutrients and a low concentration of water in their roots. This winterized condition enables alfalfa crowns and roots to withstand temperatures as low as 5° above zero.

This may not sound that cold, but remember that the soil temperature isn’t as cold as the air temperature, and the snow provides a layer of insulation to protect the plant from bitter cold. The snow also reduces the rate that soils and alfalfa roots dry out. This is why winters with little snow cover can cause more injury to alfalfa stands, especially if soils are dry.

Of course, fall management practices influence the effect of snow on your alfalfa. Tall stubble provides some insulation value and will catch more snow. Also, avoiding alfalfa harvest from mid-September through mid-October helps alfalfa roots winterize well.

Bruce Anderson
Extension Forage Specialist