Depending on region, livestock type, and forage source, it is safe to say many livestock producers could be planning to augment forage stands as soon as possible this spring. Having a better understanding of what alfalfa stands might look like in a couple of months will help guide those decisions. Alfalfa injury or death (from winter weather OR overall plant hardiness) occurs because of a myriad of factors:

• Lack of adequate drainage – poorly drained, heavy clay soils increase the likelihood of frost heaving during late weather and into early spring. Taproots become more exposed to winter weather, winds, and disease.

• Low fertility – namely potassium. Potassium increases plant health, helping defend alfalfa from disease. More importantly, potassium helps maintain sufficient energy storage in the plant. These carbohydrates keep the plant alive during the winter and help it “wake up” come spring. Late summer and fall are the perfect time to assess and supplement potassium levels, if not all soil fertility. Also, soil pH levels below 6.5 increase the likelihood of winter injury.

• Harvest timing and cutting management - harvest frequency and timing of fall cutting will affect alfalfa winter hardiness. Stands in which the last cutting is taken between early September and mid-October (for most of CISCO’s footprint) are at the greatest risk as plants will not have enough time to accumulate carbohydrate levels in their roots before winter.

• Snow cover – snow totals are down this winter, which normally means alfalfa stands are more at risk, as snow provides insulation to the plants and the crown. The crucial temperature zone is two to four inches below the soil surface where a large part of the root structure is located. Stands that have at least six inches of stubble left will be able to retain more snow cover and be less susceptible to winter injury.

• Variety- alfalfa varieties with superior winter hardiness ratings and a high disease resistance index – we have plenty of those! – are less likely to experience winter injury.

• Stand age – older stands are more likely to winter kill than younger stands, and there appears to be a large percentage of four- to five-year-old stands currently across the upper Midwest.

Whether it is winter-kill or old age, get out and check your fields. If alfalfa stands are slow to green up or appear uneven in their regrowth (due to a portion of the plant/buds being damaged), it is time to investigate further. Dig up roots and check them for winter injury.