Severe fire may kill tussocks Sheathed cottonsedge sprouts from burned tillers and establishes from seed following fire. Flower and tiller production increase after top-kill. Grazed by sheep, cattle, lemmings, ground squirrels, caribou, and geese. Seeds are first produced at age 3 and are dispersed by wind. Flower and seed production increase with disturbance.
Seeds readily germinate after overwintering when exposed to light and warm temperatures.
Live mosses or liverworts, dead leaves, and dead peat are favorable seedbeds. Seedling growth is largely controlled by nutrient availability and is most rapid after fire has released nutrients into the soil. Produces tillers at the rate of one to three per year, with tillering increasing in response to disturbance. Tillers die after flowering but decompose slowly due to compaction and low temperature. By seed, following cold stratification.