Southern Soil Winter Issue 2022, Vol 5

Native Plant Highlight: Cinnamon fern / Osmundastrum cinnamomeum

Article and photos by: Heather Brasell heather.brasell@gmail.com

This article is courtesy of the Coast Plain Chapter of the Georgia Native Plant Society. The GNPS is dedicated to promoting the stewardship and conservation of Georgia’s native plants and their habitats. The Coastal Plain Chapter serves the people in the Coastal Plain ecoregion of Georgia. This includes all areas south of the Fall Line in middle Georgia, from the Alabama and Florida borders to the Atlantic ocean. To learn more, please visit their website.

I enjoy a variety of ferns in shady places on my grounds. Even though they don’t have flowers, they provide interesting structural shapes, with a variety of textures, green colors and seasonal interest. They also provide valuable ecological benefits.

Ferns are non-flowering plants that reproduce by spores. The spores are produced in special structures on the underside of leafy fronds or on separate non-leafy fertile fronds. Most ferns are deciduous, with characteristic curled “fiddleheads” emerging from the crown in spring and gradually uncurling to develop into fronds.

Ferns are often thought of as somewhat delicate and fussy about needing moist sites but, in practice, many species are quite hardy and tolerant of a wide range of moisture and sunlight conditions. Just be prepared to water them during extended droughts.

One of my favorites is cinnamon fern Osmundastrum cinnamomeum (formerly Osmunda cinnamomea). Cinnamon fern grows in large clumps with fronds up to 5’ long. There are two kinds of fronds (dimorphic). Sterile leafy fronds have a pale

green color and frilly twice-divided shape; a whitish velvety coating on lower stems and fiddleheads becomes cinnamon colored as they mature. The rachis (stems) are green with conspicuous red-brown hairs when young, but they are nearly hairless when mature.

Fertile fronds appear in spring and early summer and are at least as long as the sterile fronds. They don’t have a leafy appearance at all. The erect cinnamon-brown colored spike with masses of brown spores resembles large cinnamon sticks. Like many other fern species, it dies back in winter.

Cinnamon fern is commonly found in wet places— floodplains, flatwoods, and around the margins of swamps and bogs. However, they tolerate a wider range of sites. They prefer soils with high organic content, but they grow well in typical loamy garden soil. They can tolerate full sun if there is plenty of soil moisture all year and they can tolerate welldrained sites if there is plenty of shade. On my property, a population of cinnamon fern thrives on a well-drained, moderately shady wooded site that is burned every 2-3 years.

Several parts of cinnamon fern have been used by Native Americans for medicine and food. Fiddleheads of cinnamon fern are edible, but sources indicate that they are not very palatable. Be careful, as all ferns contain some carcinogens; so limit the quantity that you eat and how you prepare them for eating.

Ferns don’t have flowers for pollinators, but they do have other ecological benefits. The fibrous roots help prevent erosion and filter water runoff. Ferns provide valuable foraging and shelter for ground-feeding birds, amphibians, and insects, with the advantage that they resist browsing by deer and rabbits. The fuzz that covers the young fiddleheads and the hairs on the rachis are favorite nesting material for birds.

If you have a shady area in your garden that isn’t droughty, ferns can be a beautiful addition to your garden. With lots of choices in ferns for your garden, it is worth getting to know some of the species common to the Coastal Plain ecoregion.

Some grow in separate clumps; others have spreading rhizomes that form colonies. Some are dimorphic (separate sterile and fertile fronds); others have spore-producing structures (sori) on the underside of leafy fronds. They also vary in size, color, frilly appearance, and habitat requirements. Many are good plants to consider around ponds, in rain gardens, seeps, or drains.

The following species are listed in order of theirsize.

● Royal fern (Osmunda regalis) is anotherlarge dimorphic fern that grows in clumps. Itprefers very wet sites.

● Virginia chainfern (Woodwardia virginica) and marsh fern (Thelypteris palustris) grow in colonies in wet sites. They are both fairly large (3-4’) with coarse, dark green fronds. Southern shield fern (Thelypteris kunthii) has similar characteristics but it prefers calcareous soils, thrives in deep shade (under buildings), and requires less moisture.

● Netted chain fern (Woodwardia areolata) and sensitive fern (Onoclea sensibilis) are both midsized (<18”) dimorphic ferns that grow in colonies in moist to wet sites. Their midgreen sterile fronds with wide pinnae (like leaflets) are easily confused, but their fertile fronds are distinct.

● Ebony spleenwort (Asplenium platyneuron) is a smaller, dimorphic, evergreen fern with a creeping habit. It thrives in well-drained wooded slopes.

Where can you get ferns? Don’t transplant ferns from the wild. You can find about a dozen species readily available from nurseries. Most ferns reproduce vegetatively, so you can divide them (preferably in spring before the fiddleheads uncurl) to create separate plants. You can also grow ferns from spores. It is not difficult, but it can take up to two years for ferns to be ready for planting into your garden. Collect spores in summer by placing an entire frond between newspaper. Spores drop out after a few days. They don’t need to be stratified, but you should maintain high humidity and cleanliness during propagation.

Then plant and enjoy your ferns!39

Allen, S. 2018. Native ferns have a place in our plantings for wildlife. https://loudounwildlife. org/2018/07/native-ferns-have-a-place-in-our-plantings-for-wildlife/#:~:text=From%20a%20wildlife%20 point%20of,resistant%20to%20browsing%20by%20 rabbits.

Duthie, L. 2020. Add mystery with ferns. https:// www.ecolandscaping.org/04/designing-ecological-landscapes/add-mystery-with-ferns/

Nelson, G. 2000. The ferns of Florida: A reference and field guide. Pineapple Press: Sarasota, FL.

Ontario Ferns. Cinnamon fern. http://ontarioferns. com/main/species.php?id=4004

Snyder, L. H., & J. G. Bruce. 1986. Field guide to the ferns and other Pteridophytes of Georgia. The University of Georgia Press, Athens, GA.