Send us tips/photos/videos


Native Gardening with Jimmy: Unfurling the mysteries of ferns

Christmas fern hugging a rocky slope.

Add Your Heading Text Here

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Ut elit tellus, luctus nec ullamcorper mattis, pulvinar dapibus leo.

Posted on: May 9, 2024


Christmas fern hugging a rocky slope.
Christmas fern (Polystichum acrostichoides) hugging a rocky slope.
Photo Credit: Jimmy Rogers

Ferns awaken an ancient part of my brain. Observing low, herbaceous plants on any forest floor, I will often marvel at the leafy texture. But if there are ferns, the place seems transported from another time, unexplored by human feet.

They are ancient plants, with some, such as interrupted fern (Osmunda claytoniana), dating back to the Triassic period. For the gardener, ferns can seem mysterious, as they look different from other plants and need the right conditions to grow. Few plants, however, add as much texture and vibrancy to a shade garden as a fern. I will reveal some secrets to understanding ferns so you can choose the right one for your garden.

It helps to know what you’re looking at when you encounter a fern, either in the garden or in the forest. With the exception of the semi-evergreen ferns, many ferns leave little evidence of their presence over the winter. In Maryland, our ferns start putting out curled-up fronds called fiddleheads around mid-April. The fiddleheads will grow taller and unfurl over the following weeks, displaying the delicate new fronds in bright green. If you catch fiddleheads unfurling  in the wild, it’s like seeing spring itself emerging from the winter duff.

Foraging for fiddleheads

Let us pause here to touch on foraging. There is a long tradition of collecting fiddleheads, which are edible, in the spring. In Maryland, though, all of our native ferns contain carcinogens (cancer-causing chemicals), except for ostrich fern (Matteuccia struthiopteris). It’s easy to remember: Ostrich fern is the only fern with the name of an animal you could eat! My partner, Greta, enjoyed ostrich fern fiddleheads during her time living in Maine, where they can be found in most grocery stores in the spring. She says they taste like a more delicate asparagus.

To complicate matters, though, ostrich fern is on the Maryland Department of Natural Resources rare plant list because only small populations remain along forested floodplains, such as those along the Patapsco River. To preserve these remnant ecosystems, only forage from artificial communities of ferns in Maryland, such as ferns you’ve planted in your own garden. 

The cut method

To the untrained eye, all ferns may look the same. You can narrow down the species a little by counting what are called  cuts. First imagine a normal leaf. Then imagine making a single cut from the side of that leaf. If you repeat that single cut along the length of the leaf, that is what the fronds of what’s called a once-cut fern looks like. If you then cut each of those new segments again, that is what a twice-cut fern looks like. If you made another tiny cut inward in each of those cuts, you’d end up with a leaf that looks a bit like lace. That is a thrice-cut fern.

Fern reproduction

Once the fronds are fully unfurled, the fern can enter the reproductive phase of its life. The underside of some fronds have small dots called sori. These contain spores that will spread on the wind to form new plants. 

Ferns, like many other plants, can also reproduce by rhizomes that spread underground,. Some ferns do this very quickly and are known as fast-spreading, while others take their time and are known as slow-spreading. This is both a useful way to classify them and a good way to plan how many ferns to buy for your garden.

Fast-spreading ferns

Lady fern (Athyrium filix-femina) is a short, thrice-cut fern that can spread quickly in dry shade. For wet environments, sensitive fern (Onoclea sensibilis) is a once-cut fern whose fronds resemble a primitive feather.

Slow-spreading ferns

Northern maidenhead fern (Adiantum pedatum) has a unique circular arrangement of fronds.

Interrupted fern (Osmunda claytoniana) is a twice-cut fern, though the second cut is less deep, as though the cut was interrupted. Both prefer moderate rather than deep shade and consistent moisture.

Within this group are also the semi-evergreen ferns. Marginal wood fern (Dryopteris marginalis) is a twice-cut fern that prefers moist shade. Christmas fern (Polystichum acrostichoides) is a bold, once-cut fern that can tolerate dry shade and is often found on rocky slopes.

Keep in mind that non-native ferns are frequently sold at big box nurseries. (Among these you will find Japanese painted ferns, which have a distinctive coloration.) Our native ferns have sheltered local wildlife for millions of years, though, so stick with natives to ensure that relationship continues in your own garden.

Planting ferns

Ferns require no special care when planting, though I find myself most confident planting at two times of the year. In the fall, the ferns you can buy will often have fading fronds but perfectly good roots. Fall planting will give them the most time to adapt to their new environment. For spring planting, I prefer March or April, as nursery-grown ferns will just be emerging from dormancy, and I will be able to tell if they are viable. Any later in the season, and you risk damaging the first flush of new fronds in summer’s heat.

To ensure good ground coverage in early spring, do be sure to combine your ferns with other plants that come up earlier in the season.. As your shade plants grow more dense over time, those unfurling ferns may help your garden  resemble the beauty and mystery of a primordial forest.



The Streetcar Suburbs Spotlight

Local news and events straight to your inbox

Free! Cancel anytime.

Have a tip?

Send us tips/photos/videos

Related Posts

Laurel Mainstreet Festival Delights

On May 11, 2024, Laurel gathered to celebrate local businesses with a day full of fun. There was a parade as well as vendors and...

Local Results from the May 14, 2024 Elections

On May 14, 2024 people across Maryland flocked to the polls to vote in the state’s primary elections. U.S. Senate candidate Angela Alsobrooks won the...

County schools grapple with lead in drinking water

By SAM GAUNTT As many as 150 of Prince George’s County’s 209 public schools have lead in at least some water faucets, pipes and hoses,...