Found on poorly drained low ground and in thickets, wet marshy woods, swamps, ditches, and streambanks. It is generally found in ombrotrophic bogs, but it also grows on minerotrophic wooded island hummocks in peatlands. Where humidity is very high cinnamon fern can sometimes be found on better drained soils. Although fronds are probably killed by fire during the growing season, cinnamon fern sprouts from rhizomes after the aerial portions are burned. Cinnamon fern has good fire tolerance and shows vigorous rhizome growth after fire.
Spores germinate on mineral soil, so cinnamon fern probably colonizes after fire.
Survives fires in many habitat types and may increase in cover. However, if the fire is so intense or of such duration that it burns the organic substrate completely, cinnamon fern will be lost. Spore germination in liquid medium is useful for bioassay of toxic opper, cadmium, and zinc concentrations. Both sterile and fertile fronds expand during a short period in early spring. Leaf expansion is complete within about a month.