Check alfalfa stands for winter injury as we wait for fields to dry

Now is the time to check alfalfa stands

Late last week, as I walked through an alfalfa field on my way to a 2024 corn field that will be planted to a soybean experiment this spring, alfalfa re-growth was spotty at best (Figure 1). A look from a distance hinted at decent survival and regrowth, but upon closer inspection, many of the green plants observed were dandelions.... 

Figure 2 illustrates that the lack of insulating, protection-providing snow cover didn't kill every plant.

Figure 1. An alfalfa stand near Gary, MN in late April 2025. Note: most of the green is dandelions. 

Figure 2. Some lone alfalfa crowns showing signs of life surrounded by many more that were not. 

Assess plant health, plant population and stem density

There are three things that one should look at to determine whether an alfalfa crop is likely to be productive enough to keep, needs rehabilitation or should be scrapped and another forage crop seeded. Briefly, from multiple areas of the field, 1) dig plants to a six-inch depth and then split and examine roots for overall taproot health, 2) determine the density of living plants per square feet and 3) count the number of living stems per square-foot. 

Information about what healthy alfalfa taproots look like and how many plants and stems per square foot should be sufficient for a productive crop are detailed on a UMN Extension website devoted to assessing alfalfa winter injury, as is information about managing injured stands and options for reseeding.