There are places where even ferns won’t grow, particularly in areas where there is no sunlight, such as inside caves and under bridges.
However, ferns perform well in low-light conditions in woodlands and shady north- and east-facing wooded slopes. In general, ferns need the shade of canopy and understory trees, so let’s begin there.
Types of trees
Not all canopy trees are compatible with ferns or other plants.
Maples produce a shallow, dense root system that prevents other plants from growing under them. If you walk through a sugar maple forest, you will discover that the understory is empty, like a desert.
Mature hackberries and bald cypress also are difficult for the same reason, although the roots are a bit more forgiving to plant under.
However, trees such as black walnuts, oak, hickory, pine, elm and black gum are ideal trees to garden under because their trunklike roots are coarse and spread far apart and wide. This allows ferns and other wildflowers to grow roots between the tree roots. I particularly love gardening with shortleaf pine and black gum because they grow fast, are tall and narrow, and fit in small garden areas.
Native understory trees such as red and Ohio buckeye, rusty blackhaw viburnum, flowering dogwood, pagoda dogwood, spicebush, serviceberry, witch hazel, pawpaw, persimmon, redbud, wild plum, hornbeam and hop hornbeam also work well with ferns. They are small flowering trees that fit well in tight residential spaces.
UNIQUE LOOK: These sensitive ferns grow rather large. They have a course texture and grow well in wet conditions, such as under thick tree canopies.
The easiest native ferns to grow and buy are sensitive fern, Christmas fern, ostrich fern, maidenhair fern, royal fern, lady fern — and the fern relative, scouring rush. These are relatively easy to grow in gardens and are rabbit resistant. Each have special needs and uses.
Ostrich fern, sensitive fern and scouring rush rely on suckers to form groundcovers. Ostrich fern fiddleheads (unfurling fronds in early spring) are edible.
Scouring rush, with upright rushlike, rigid stems, is very aggressive and should either be contained or let go to form large colonies.
Christmas ferns are clump-forming and grow relatively slow. They are the most drought-tolerant of the above ferns and are evergreen.
Lady and maidenhair ferns need supplemental watering to stay green during drought periods and must be protected from overcrowding by neighboring plants.
Sensitive and royal ferns grow well in wet sites such as shady rain gardens and poorly drained low areas.
There are about 70 fern species that grow wild in Missouri, yet fewer than a dozen native species are available commercially in the Midwest and southeastern U.S. because ferns are difficult for nurseries to propagate.
Shaw Nature Reserve sells a handful of species. The next-closest native plant nurseries who sell native ferns are Prairie Nursery in Wisconsin and North Creek Nursery in Pennsylvania. Local vendors may have some in stock. Check the online GrowNative! resource guide for information.
Horticulturist Scott Woodbury is the curator of the Whitmire Wildflower Garden at Shaw Nature Reserve in Gray Summit, Mo., where he has worked with native plant propagation, design and education for 27 years. He also is an adviser to the Missouri Prairie Foundation’s Grow Native! program.