It can withstand some soil disturbance. Sweet grass was a major component of the meadow zone just above high water on the Churchill River in northeastern Manitoba. This was the earliest closed-cover successional community on the flats. Sweet grass was a minor component of undisturbed and disturbed dry grassland sites in northeastern Alberta. Sweet grass was a minor component of the meadow stage of succession on gravel outwash terraces in south-central Alaska.
Sweet grass is among the earliest flowering of Alaskan grasses.
Seedheads are formed in autumn and remain small and hidden through winter in the new growing shoots, which elongate the following spring. Seedheads appear early in May, almost as soon as the grass begins spring growth.