Ornamental · Dryopteridaceae
Autumn Fern
Dryopteris erythrosora
Tuck it into moist shade and the autumn fern rewards you with copper-red new fronds that brighten the season.
Partial shade
Every 5–7 days
USDA 5–9
18–30 in · 45–76 cm
Overview
The autumn fern is a tough, good-looking woodland fern from East Asia, and it is loved for the copper-red color of its new fronds. Those fronds open bronze to orange-red in spring and then deepen to a glossy green as the months roll on. It keeps its shape through the cold and stays evergreen in milder gardens, so your bed never has to look bare, and that alone makes it a comforting plant to grow.
What makes it such a kind choice for a nervous beginner is how forgiving it is. Give it the shade and steady moisture it enjoys and it asks for little else, and once it has settled in it shrugs off dry shade and short dry spells better than most ferns. Deer tend to walk right past it too, which takes one more worry off your plate at a woodland edge.
One thing worth thinking through before you plant: it travels along by underground rhizomes and can spread further than you expected. North Carolina Extension flags it as potentially weedy, so do have a quick look at your regional guidance before you settle it into the ground, and you will be glad you did.
Care
The short version: part to full shade in rich, humusy soil that stays evenly moist. Water it faithfully through the first season to get it going, tidy up the old fronds in late winter, and from there it really does look after itself.
Light
Give it part to full shade, the soft dappled light you find on a woodland floor. It will happily take some morning sun, but harsh afternoon light scorches the fronds unless the soil stays reliably moist, so a little shade goes a long way.
Water
Keep the soil evenly moist, above all through that first growing season while the roots are settling in. Watering every 5 to 7 days suits most spots, and once it has found its feet the fern handles short dry spells and dry shade better than most, so a missed day now and then is nothing to fret over.
Soil
Plant it in humus-rich, well-drained loam full of organic matter. A slightly acidic pH of 5.0 to 6.5 suits it best, and a generous helping of leaf mold or compost keeps the ground nicely moist without letting it turn soggy.
Temperature
It is wonderfully hardy and cold-tough, taking winters down to -20°F (-29°C) and warmth up to around 86°F (30°C). That range covers USDA zones 5 through 9, and in the milder end it stays evergreen for you.
Humidity
Average humidity of around 40% to 70% keeps the fronds looking their best. Like most ferns it isn't keen on dry air, so a shaded, sheltered spot with moist soil does far more for it than chasing any single humidity number.
Feeding
This is a gentle light feeder, so there is no need to overdo it. A spring topdress of compost or leaf mold feeds it beautifully, or you can use a balanced slow-release fertilizer just once as growth gets going.
Pruning
It barely asks to be cut back at all. In late winter to early spring, before the new fronds unfurl, clear away any tattered, old, or winter-damaged fronds to make room for the fresh growth coming through.
Repotting
If you grow it in a container, repot it every 2 to 3 years, or whenever roots push from the drainage holes and the soil dries out fast. A crowded rhizome lifting at the surface is another friendly nudge that it would like more room.
Size & spacing
Expect a tidy clump 18 to 30 inches (45 to 76 cm) tall that spreads 24 to 35 inches (60 to 90 cm) wide. Leave a little room for that spread, and remember it can creep further by rhizome over time, so a roomy spot saves you fuss later.
When to plant
There are no flowers to time with this fern and no harvest to chase, so planting is the only date you need to remember, which keeps things lovely and simple. Set it out in spring once the frost has passed, or in early autumn while the soil is still warm enough for the roots to settle in before winter arrives.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: Spring after last frost, or early autumn
Hardiness
USDA hardiness zones: 5–9
Temperature: down to -29°C
Troubleshooting
Nearly every hiccup with this fern shows up in the fronds, and most of them trace back to too much sun, too much wind, or the wrong amount of water. Read what the fronds are telling you and the fix is almost always an easy one. Find your symptom below and act gently before more fronds follow along, and the plant will bounce back.
Browned, bleached frond edges after hot sun
Don't worry if the frond edges look bleached or brown, because this is just sun scorch and it usually comes with soil that has gone too dry. You will notice it most on the fronds that sit in hot afternoon light. Ease the plant into deeper shade or shade it where it stands, then water it deeply and add mulch to lock that moisture in. Snip off the worst fronds and gentle new ones will soon take their place.
Fix:
- Relocate or shade plants receiving harsh afternoon sun
- Water deeply and mulch to retain soil moisture
- Trim badly damaged fronds to encourage fresh growth
Yellowing fronds and a fern losing steam
Yellowing that spreads across the whole plant is usually a moisture problem at the roots, and it can lean one of two ways. Soggy, waterlogged ground smothers the roots, while soil that keeps drying out leaves them thirsty, so take a moment to feel which way yours is going before you do anything. Mix in some organic matter or lift the fern off standing water to help it drain, then settle into a gentle, steady routine that keeps the soil evenly moist. The plant forgives a wobble once you find its rhythm.
Fix:
- Improve drainage by adding organic matter or relocating from standing water
- Establish a consistent watering routine to keep soil evenly moist
Tattered, wind-torn fronds on the exposed side
When strong, drying wind gets at the soft fronds, it frays their edges, and the tearing shows up on the side facing the breeze with no spots or pests alongside it. There is no harm done that you cannot fix, so trim away the battered fronds and offer the plant a sheltered nook or a little windbreak. A calm, protected woodland corner will keep the foliage whole and lovely.
Fix:
- Remove damaged fronds
- Provide a sheltered planting position or windbreak
Toxicity
No source confirms this fern is poisonous, and its close relatives like the Boston fern are listed as safe for pets, which is reassuring. But no source confirms this exact species is safe either, so the honest answer is that the data simply isn't there yet. Until it arrives, keep pets, livestock, and children from chewing the fronds as a sensible, caring precaution.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Caution
Take heart that no source names this fern as poisonous to cats, and gentle cousins like the Boston fern sit on the safe list. Even so, a cat that nibbles a frond might drool a little or bring some back up, so it is kindest to keep it out of reach until the species is cleared.
Dogs Caution
There is nothing on record showing this fern harms dogs, and its shield fern relatives are counted as non-toxic. A curious pup that chews a frond could still end up with a mild tummy upset, which is good enough reason to steer it away.
Horses Caution
No source marks this fern as dangerous to horses either way, good or bad. Without that reassurance in hand, keep grazing horses clear of it and simply watch for any drooling or dullness if a mouthful goes down.
Rabbits Caution
Rabbits do not appear in any toxicity entry for this fern, so its safety for them is just unproven for now. Offer none of it while that gap remains, and if a frond gets chewed, keep a calm eye on your bunny.
Livestock Caution
Cattle, goats, and sheep show no recorded reaction to this fern, neither helpful nor harmful. Fence it away from grazing stock as a gentle precaution rather than trusting that it is fine.
Birds Caution
Nothing on record tells us how birds get on with this fern. Keep pet and backyard birds away from the fronds until a trustworthy source has its say.
People Caution
No part of this fern is meant for the dinner plate, and no source vouches for it as something to eat. Gently keep children from chewing the fronds, and never treat it as a wild snack.
No documented toxicity, but no confirmed safety data for this exact species; discourage pets and children from chewing the fronds as a general precaution.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
Poison Control: (800) 222-1222
Canada
Poison Centres: 1-844-764-7669
Varieties
A couple of named selections turn up alongside the plain species, and each brings its own gentle twist on color or habit.
'Brilliance'
Its fresh spring fronds open in a brighter, deeper red than the plain species, and they hold that lovely color well into the season.
var. prolifica
A slender, finely cut form that sprouts tiny plantlets along the frond stem, giving it a charming second way to spread on its own.
How to propagate
The autumn fern is wonderfully simple to multiply, and dividing an established clump is far and away the easiest path to more plants.
DivisionEasy
Spring or early autumn · 1 to 2 growing seasons
Division is the gentle, easy route, and it is hard to go wrong with it. In spring or early autumn, lift an established clump and tease it apart into sections, leaving roots and fronds on each piece, then give the divisions a season or two to settle in and fill out. You can also coax new plants from the spores ripening on the frond undersides, though that path is much slower and asks a bit more patience of you.
Myths
Autumn fern is named for foliage that goes copper once fall arrives.
The lovely coppery bronze to orange-red shows up on the new fronds as they unfurl in spring, then mellows into a glossy deep green by summer. The name describes spring, not fall. What does turn orange-red in autumn is the ripe spores tucked on the undersides of the fronds.
Any fern will poison a cat or a dog.
Plenty of true ferns in the same family, the Boston fern and sword fern among them, are listed as non-toxic to pets by the ASPCA. But no source confirms the status of this exact species, so the kindest move is simply to keep pets from chewing the fronds rather than assume it follows its relatives.