Planting the perennial layer in the shade garden is the fun part since there are so many great plant choices and they don’t require such an effort to plant. Also, if you happen to be working on hot day, you’ve got it made in the shade (sorry, I couldn’t help myself).
I once took workshops on meadows and woodland gardens from a well-known designer named Darrell Morrison who did all of the meadows at Storm King. He said that meadows or meadow-like gardens should be 80% grasses and woodland gardens should be 80% ferns. I am not quite that dogmatic but I do believe that ferns are an essential component of the woodland garden. There are so many great ferns that do well in our Catskill environment and I have never seen a deer-munched fern. If I could only have one, I would choose the Ostrich Fern, Matteuccia struthiopteris, (forgive me, I feel like I have to include the botanical names; I will save the lecture on their importance for now). The Ostrich Fern is big and luscious, it spreads and fills in and the emerging frawns are so beautiful and extremely tasty when we call them fiddleheads. Don’t take more than 33% of the fiddleheads emerging from one crown if you want to keep having a healthy fern.
There are other big ferns that grow naturally in our woodlands that are not as easy to come by in the nurseries but are really cool: the Cinnamon Fern (Osmundastrum cinnamomeum), the Bracken Fern (Pteridium aquilinum) and the Lady Fern (Athyrium filix-femina) are all good choices and also produce “fiddleheads”. The Cinnamon Fern is particularly striking with the stiff spore-bearing frawns that appear early in the spring followed by the fiddlehead frawns. This and the Bracken Fern can grow 4 feet tall in the right conditions; the Braken Fern can be very aggressive as well. The Lady Fern is a little smaller and has a more delicate, lacy and lilting feel. There are numerous cultivars of the Lady Fern but the only one I have am really familiar with is the Lady in Red which has light green foliage held upright on dark, brilliant red-violet stems (called stipes in fern speak). It is beautiful and the reddish stems add a litte spice.
Like the grasses in the meadow, the ferns act as the stitchers in the woodland garden creating a backdrop like a tapestry for the other woodland plants. Two of the most aggressive filler ferns are the Hay-scented Fern (Dennstaedtia punctilobula) and the Sensitive Fern (Onoclea sensibilis). I consider the Hay-scented Fern to be the most generic fern; it is the one that takes over the forest floor when there is a high canopy. While it is quite beautiful in these masses it will shade out any new saplings and block them from growing and regenerating the forest. The deer eat the young saplings giving more advantage to the hay-scented ferns, that the deer don’t eat; then the ferns fill in and make it really difficult for new saplings to get past deer height resulting in the “totally blown out” (TBO) forest in our area. The Sensitve Fern can get quite large; it has coarser textured frawns that add a nice contrast to the fern collection. This fern is also very aggressive and needs to be sited with caution but can be a very useful addition to the mix. It is easy to establish and will definitely thrive in most conditions.
Any of these fern choices look great planted in masses but some work well as specimens or small groupings because of their extra ornamental value. The Nothern Maidenhair fern (Adiantum pedatum) has a very different look and more delicate texture that is beautiful up close. Ideally it should be near the path or edge of the garden where it can be seen. The same can be said for the only non-native fern I am recommending, the Japanese Painted Fern (Athyrium niponicum ‘Pictum’). It has a spectrum of beautiful colors that range from a deep burgundy through green to a frosty silver color. Japanese Painter Ferns provide a special addition and colorful selection and deserve a prominent place in the garden.
There are a couple of evergreen ferns that I love and always use in a woodland garden. The Christmas Fern (Polystichum acrostichoides) is shorter and has dark green, waxy looking frawns that look great as an accent amongst the rocks or lighter colored ferns. The Marginal Fern (Dryopteris marginalis) also known as Marginal Shield Fern, Eastern Woodfern or Marginal Woodfern.. The Marginal Fern, while pretty is also pretty generic looking similar to the Hay-scented Fern. However it is well-behaved and evergreen which makes is a much better choice for many situations.
Lastly I really love the Royal Fern (Osmunda regalis) and the Autumn Fern (Dryopteris erythrosora) but these are not as top of mind for no good reason except that I guess I just don’t see them as often. The Royal Fern can get quite large and has some of the characteristics of the Ostrich Fern and Sensitive Fern except it is not aggressive and is happier in wetter areas.
Most of the ferns mentioned here can work in quite shady situations but prefer part shade or dappled shade. Some of them do better in moist soils than others, but they all do pretty well in average woodland garden situations.