They are native to central and northern North America from Newfoundland to Alaska and south to Virginia, Europe and Asia. The Asian variety is, I understand, larger in all its parts than that found in North America. They are rated hardy from USDA zones 2 to 8. Some of my gardening friends in southern Virginia and North Carolina have said that Ostrich Fern is difficult for them to grow, so it may be that it only does well in the colder parts of USDA zone 7 on the East Coast. They really do like moist soil and suffer when it is too dry.
Dry conditions can bring on early dormancy.
This has happened to me once during a drought when all my watering just wasn t enough. Ostrich Ferns can be grown in shade to semi-shade, tolerating more sun in swampy conditions. Fronds arise from a tufted, woody rootstock that is visible above ground, and the fern spreads by underground rhizomes. I wish it would increase more for me. Fertile spore is carried on separate fronds that appear in the center of the clump in summer instead of in sporangium on the back of each frond.