They don’t have big showy flowers (or even tiny inconspicuous flowers), they don’t feed pollinators or even rabbits (usually), and only a few seem to be host to some moth caterpillars, but it is my firm belief that every native plant garden should have ferns.
There are native ferns for just about every garden condition in the Southern Great Lakes region. After all, according to the Peterson Field Guide to Ferns of Northeastern and Central North America, “some 11,000 different species of ferns and fern relatives… occupy every corner of Earth, from mountaintops to deserts to coastal swamps.” That book covers over 100 species that are mostly native to our region. There WILL be a fern that will grow in your garden.
In this month’s article I will take a look at some of the ferns I have in my own garden in southwestern Ontario (as well as a couple I don’t have) and I will discuss why I like them. I have at least 18 species of ferns in my gardens – I have had more in the past, but lost a few over the last couple of years due to changing conditions in my yard.
My Top 10 Ferns
The following ferns are ones that just about anyone can grow in their gardens. They tolerate a wide range of soil moisture and/or light requirements and are long lived. (The plants are listed alphabetically by scientific name.)
Maidenhair Fern (Adiantum pedatum) – If you have a moist, humusy, full-shade garden, there are few ferns that add as much delicate beauty as the clump forming Maidenhair Fern. Also known as the Northern Maidenhair Fern, the Five Fingered Maidenhair Fern or simply the Five Fingered Fern, these ferns will tolerate some sun, providing they are kept moist.
This deciduous fern has black, shiny stems that reach up from a creeping rootstock to form a horseshoe-shaped semi-circle of horizontal bright green fronds. Maidenhair Ferns can get up to 3’ tall, but more commonly tops out around 18-24”. This is, apparently, one of the most sought-after native ferns at garden centres, and for good reason. An excellent choice for a full shade rain garden or bog garden, it regularly gets oohs and aahs from visitors to my yard. My only wish is that it would spread a little more aggressively – it seems to take forever.
Lady Fern (Athyrium filix-femina) – A gorgeous 2-3’ tall fern that gets as wide as it is tall, Lady ferns provide a delicate lacy look to the flower bed. This fern prefers dappled shade and moist to mesic conditions in any loose loamy soil, but will tolerate a fair amount of morning sun and I have seen it growing in full shade in forests.
I have a robust specimen that anchors the corner in a shady garden. Small offsets form at the base, allowing this fern to spread – albeit VERY slowly. My specimen is close to 15 years old and is less than 2’ across at the base, but its full bushy nature makes it look much larger.
Bulblet Fern (Crystopteris bulbifera) – If I had to pick just one fern to grow in my garden, it would be this one. In early spring, the bright red stalks are very showy. The fronds will get quite long (up to 30”), but they tend to flop over and, in my garden at least, seldom get higher than 12-18”. They do work well in planters, though, providing a lovely cascading effect.
The plant gets its name from the tiny “bulblets” that grow on the underside of the fronds (in addition to the typical sori – groups of spores – that are found in ferns). These bulblets fall to the ground where, if the conditions are suitable, a new fern will spring up.
Bulblet Ferns – which have a number of common names including Bulblet Bladder Fern, Bulblet Fragile Fern, and Berry Bladder Fern – are a garden winner in many regards. In a low, moist area of my yard, these tiny ferns grow in full sun and maintain a reddish brown tinge throughout the summer. But I also have them growing in full shade in an old claw-foot bathtub, where I never water them and even in the driest years they have stayed green and fresh looking all summer long.
Crested Wood Fern (Dryopteris cristata) – New in my garden this past year, I’m loving the delicate look of this little (1-2’) clumping fern. It prefers part to full shade, but will even grow in full sun if sufficiently moist. It spreads slowly by short creeping rhizomes and, given sufficient time, can produce a nice, dense groundcover.
This fern is considered semi-evergreen as the fertile fronds tend to collapse during the winter, but the sterile fronds remain green all winter long. Also known as Buckler Fern, Crested Shield Fern, or Narrow Swamp Fern, this is a good choice for loam to clay soils.
Ostrich Fern (Matteuccia struthiopteris) – At up to 4’ tall when mature, this fern is super easy to grow in clay to sandy loam, full shade to mostly sun (with sufficient moisture) – though dappled shade is best – and dry to seasonally wet soil. In very dry soils, such as under a Sugar Maple tree, it may go dormant partway through the summer. It tolerates flooding in the spring so is ideal for that low spot where the snow meltwater collects.
It is a slow but persistent spreader and may not be suitable for small gardens. Ideal companion plants are Virginia Bluebells (Mertensia virginica), Trilliums, and Bloodroot (Sanguinaria canadensis), all of which bloom then begin to fade away just as the Ostrich Fern begins to fill out. Oh, and the unopened fronds are the edible fiddleheads you can find in specialty grocers in the spring.
For me, a key identifying feature is the badminton shuttlecock (“birdie”) form of the plant.
Sensitive Fern (Onoclea sensibilis) – Sensitive Ferns are not particularly drought tolerant but they will do OK in average garden soils as long as they aren’t allowed to get too dry. They do prefer consistent moisture. Their strength, though, is that they tolerate full shade to full sun, though they may turn yellow without a bit of protection from the afternoon sun. In my garden, these ferns rarely get taller than 2-3’, though the literature suggests they will get up to 4’ tall. They tolerate most soil types, from sandy loam to clay.
They will form dense colonies but don’t spread as quickly as Ostrich Ferns and make a great ground cover in moist, partly shaded areas. Their woody-like fertile fronds persist through the winter and provide interest in the garden year-round. They get the moniker “Sensitive” because they are very sensitive to frost.
Royal Fern (Osmunda spectabilis formerly O. regalis, the latter name now reserved for the European species) – Royal fern is one of the tallest ferns we have, reaching up to 6’ in rich, moist to wet soils in full to part shade. It can even take periods of standing water. It very wet conditions, it will even tolerate full sun.
I’ve been growing this in less than ideal conditions for the past 5 years and my plants rarely get over 3’ tall, but this past summer I built a mini artificial wetland and moved some to that area. I’m hoping it will take off next year in its new home.
The leaflets of Royal Fern look a bit like a locust tree or a vetch, and its size makes it more shrub-like than what we typically think of a fern. Fronds typically turn yellow to brown in autumn. Spores are located in brown, tassel-like, fertile clusters at the tips of the fronds, thus giving rise to the additional common name of flowering fern for this plant. Osmunda fiber used in the potting of orchids comes from the fibrous roots of these ferns.
Smooth Cliffbrake (Pellaea glabella) – Difficult to find, and very fussy about its growing conditions, but if you have large limestone rocks in a lightly shaded area (or full sun, if moist), these tough little ferns are worth seeking out. They are a very small fern, only getting from 1” to 15” tall, but they will grow out of seemingly soil-less rock so they don’t have to worry about competition.
They are found on limestone cliffs in full sun to part shade. In appropriate conditions, this hardy little fern is evergreen, but here in my southwestern Ontario garden, growing on a dry “escarpment”, it turns brown and looks completely dead in the winter – though the fronds remain. With the first mild wet weather, the fern perks right back up and turns green again. The same thing happens during a summer drought. More than once I was sure the fern was dead, and then a nice rainy day brings it right back to life. It is an extremely slow grower.
A close cousin, Purple Cliffbrake (Pellaea atropurpurea), can be differentiated as it has a hairy stem instead of a smooth one. It is also much rarer (considered vulnerable in Ontario and imperiled in Michigan).
Christmas Fern (Polystichum acrostichoides) – This long-lived (15 years, or more), medium sized fern (18-24”) is one of only a handful of native ferns that is evergreen – retaining its shiny green leaves right through to the spring. They do flatten down in the winter, but still provide shelter for small birds and mammals, and nesting materials in the spring.
A forest floor inhabitant, it prefers moist, full shade, but will tolerate dappled sunlight if kept moist. They don’t do well in heavy clay soils, but they don’t mind pretty much any other soils, including average garden soil where a weekly watering will keep them green and healthy. Once established, they will tolerate periods of drought and would make a good filler plant in a shady rain garden.
Easily recognizable in the winter (because it’s evergreen), a simple way to recognize Christmas Fern in the summer is the “thumb” on the individual leaflet (see image below).
Marsh Fern (Thelypteris palustris) – This low growing (6-12”), sun loving fern is great in a bog garden, a rain garden, or any other place where it can be kept moist (though it doesn’t like standing water). The delicate leaves can form dense mats, which help to provide necessary cool shade for the roots of things like Showy Lady’s Slipper orchids (Cypripedium reginae). This fern prefers rich, acidic, sandy loam but will survive in just about any garden soil, as long as it is moist. For a fern that is so delicate looking, it really is a tough plant. Other names for this fern are Marsh Shield Fern, Northern Marsh Fern and Eastern Marsh Fern.
It is very similar to New York Fern (formerly Thelypteris noveboracensis, now known as Amauropelta noveboracensis), which can tolerate a bit drier conditions and would make a good substitute. Keep in mind, though, that New York Fern can become a dominant understory species and may out-compete the seedlings of certain tree species. The seedlings of Wild Black Cherry (Prunus serotina) are especially vulnerable, as the fern releases an allelopathic phenol which can kill them.
Cinnamon Fern (Osmunda cinnamomea) – Cinnamon Fern has gorgeous fall colour, prefers part to full shade and will tolerate full sun if it is in standing water. It will grow in most soil types, including muck, and can get almost as tall as its cousin, the Royal Fern. This is a great pond or bog plant.
I don’t include it in my top ten ferns simply because I have not had great success keeping it alive. I’m on my third attempt to grow Cinnamon Fern and I may have to move it to a wetter area than where I have it now. But it is quite gorgeous – especially in the fall.
Ferns for More Experienced Gardeners
The ferns in this section really aren’t for beginners. That’s because they are a little fussier on their growing conditions, and/or they are very aggressive spreaders. But if you have the space and/or the appropriate conditions and/or the experience and want to try something interesting, these are, in my opinion, some lovely ferns to add.
Hay Scented Fern (Sitobolium punctilobulum) – A beautiful fern for large areas, it is an aggressive spreader that gets 1-3’ tall and gives off a scent of crushed hay in late summer.. Prefers light shade and moist to mesic soils but will grow in a wide range of conditions.
Bracken Fern (Pteridium aquilinum) – Full to part sun, drought tolerant once established, this very aggressive spreader is not suitable for small spaces. However, it is so tough that I have read that it will actually thrive in the dry shade under sugar maples (but I haven’t tried it – yet). As I’ve seen it growing along roadsides in sandy soils, it might make a good plant for a Hell Strip (boulevard) garden. It gets up to 4’ tall.
Hart’s Tongue Fern (Asplenium scolopendrium) – I’ve tried to grow this rare (it is classified as “vulnerable” in Ontario), very unusual looking fern twice, in two different locations, but couldn’t keep it alive past the first year. A friend, however, has it growing beautifully in his yard. It wants part to full shade in rich, moist but well drained soil.
Maidenhair Spleenwort (Asplenium trichomanes) – This extremely delicate looking fern grows in full to part shade in rich, moist, well drained soils, and rocky terrain. I’ve seen it growing in crevices in limestone alvars with virtually no soil at all. It is small, about 6” tall, and is evergreen.