Get to Know Your Grasslands: Winterfat

With winter coming to an end, we’re reflecting on the winter grazing season and the plants that make it possible for cattle to thrive on rangelands even in cold weather. One of those native plants is winterfat, also known as lambstail, sweet sage or winter sage.

Winterfat is a native sub-shrub (a plant with a woody base and more herbaceous branches) and is known for its drought and saline tolerance while also being very winter hardy.  It is widely distributed in arid plant communities of western North America, from Saskatchewan and Manitoba, down to western Nebraska, Colorado, west Texas, California and Washington. However, winterfat does not thrive in high moisture areas or acidic soils. Identified by its long, thin leaves that are covered in small, silk-like hairs; winterfat can resemble sage plants due to its silvery-grey colour, but it lacks the strong sage smell. The flowers are small,fluffy/woolly, and resemble small cotton balls.

 

Due to the plant’s ability to adapt in drought conditions as well as long, cold winters, it is well suited to Saskatchewan’s grasslands. It also boasts an interesting root system by having both deep tap-roots as well as extensive fibrous roots near the soil surface. This can make it a top choice for native grass restoration and reclamation by having those root systems to stabilize the soil and avoid erosion. This root system also contributes to its ability to thrive through drought conditions by reaching deeper moisture levels, not accessible to all plants.

Ranchers have utilized winterfat for years as an excellent source of crude protein for livestock in the winter months. While the crude protein levels in many forage species decrease into the fall and winter, winterfat retains crude protein levels between 9-14%. Even mature plants that have reached 3 feet tall are still highly palatable and digestible, with protein levels remaining adequate for lactating animals.

 

Winterfat will do best when grazed while dormant in the late fall and winter. Studies have shown that timing of grazing may have a larger impact than duration of grazing. While very early spring followed by rest may allow the plants to recover to pre-grazing size by the end of the summer, winterfat is highly sensitive to grazing during June-August. Like any other native plant, they are sensitive to overgrazing regardless of the time of year and must be managed as a sensitive resource.

If it is overgrazed or being introduced to a new area, winterfat can be difficult to establish for a variety of reasons, including seed viability. If seed is stored for an extended period of time, it quickly loses viability, as much as 50% within the first year. Seeds seem to germinate well with early spring seeding if moisture is appropriate but most lean towards broadcasting in the fall or winter since the freezing and thawing cycle can open shallow cracks in the soil for the seed to germinate without the threat of it being sown too deep. The seeds are encased in fruits that are actually covered in tiny hairs called bracts which can cause uneven flow through drills so broadcasting is recommended, since mechanically removing the bracts can cause further issues with decreased seed viability.  When purchasing winterfat seeds, it is important to purchase seeds that were produced close to home, as some of the ecotypes from further south in the states will be less well adapted to our cold winters.

 

Winterfat can also play a pivotal role in providing habitat for species at risk. It is an excellent forage for deer, elk and birds and also contributes to the sage brush communities that birds and some even some reptiles, such as the Eastern Yellow-bellied Racer, require for survival. Keystone species, including the Greater Sage Grouse, which need large expanses of grasslands with healthy sage plant populations, are able to use winterfat shrubs for forage, nesting and hiding from predators.

 

Winterfat plays a variety of roles on Saskatchewan grasslands that not only wildlife but ranchers can benefit from having it around. When managed properly, with appropriate periods of rest, winterfat shrubs can live up to 100 years, making them a long-term resident and one worth having around.

 

Authors: Marika Sherman and Mindy Hockley-Anderson