Ornamental · Dryopteridaceae
Autumn Fern
Dryopteris erythrosora
Drop it into moist shade and the autumn fern kicks off the season with copper-red new fronds.
Partial shade
Every 5–7 days
USDA 5–9
18–30 in · 45–76 cm
Overview
The autumn fern is a tough, head-turning woodland fern from East Asia, grown above all for the copper-red color of its new fronds. Those fronds burst out bronze to orange-red in spring, then deepen into a glossy green as the year rolls on. It keeps its shape through the cold and stays evergreen in milder gardens, so the bed never goes bare.
Here is what makes growing it so satisfying: it pays you back for next to no effort. Hand it the shade and steady moisture it craves and it asks for almost nothing more, and once it settles in it powers through dry shade and short dry spells better than most ferns. Deer tend to skip right past it too, which makes it a winner along a woodland edge.
One thing to size up before planting: it creeps along by underground rhizomes and can spread further than you bargained for. North Carolina Extension flags it as potentially weedy, so check your regional guidance before it hits the ground.
Care
The short version: part to full shade in rich, humusy soil kept evenly moist. Water it through the first season to launch it, tidy the old fronds in late winter, and from there it pretty much runs itself.
Light
Hand it part to full shade, the dappled light of a woodland floor. It will take some morning sun no trouble, but harsh afternoon light scorches the fronds unless the soil stays reliably moist.
Water
Keep the soil evenly moist, above all through that first growing season while the roots dig in. Watering every 5 to 7 days hits the mark in most spots, and once it settles the fern powers through short dry spells and dry shade better than most.
Soil
Plant it in humus-rich, well-drained loam loaded with organic matter. A slightly acidic pH of 5.0 to 6.5 suits it best, and a hearty dose of leaf mold or compost keeps the ground moist without going soggy.
Temperature
It is hardy and seriously cold-tough, shrugging off 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 it stays evergreen at the milder end.
Humidity
Average humidity around 40% to 70% keeps the fronds firing. Like most ferns it hates dry air, so a shaded, sheltered spot with moist soil beats chasing any single humidity number.
Feeding
It is a light feeder, so go easy. A spring topdress of compost or leaf mold fuels it nicely, or hit it once with a balanced slow-release fertilizer as growth kicks off.
Pruning
It barely needs a trim. In late winter to early spring, before the new fronds unfurl, clear out any tattered, old, or winter-damaged fronds to open up room for fresh growth.
Repotting
Growing it in a container? Repot every 2 to 3 years, or the moment roots push from the drainage holes and the soil dries out fast. A crowded rhizome lifting at the surface is another shout that it wants more room.
Size & spacing
Look for a clump 18 to 30 inches (45 to 76 cm) tall spreading 24 to 35 inches (60 to 90 cm) wide. Leave room for that spread, and remember it can creep even further by rhizome over time.
When to plant
No flowers to time, no harvest to chase, so planting is the one date that matters and that keeps things wonderfully simple. Get it in the ground in spring once the frost clears, or in early autumn while the soil still holds enough warmth for the roots to dig in before winter.
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 snag with this fern shows up in the fronds, and most trace straight back to too much sun, too much wind, or the wrong amount of water. Read what the fronds are telling you and the fix usually clicks into place fast. Match your symptom below and jump on it before more fronds follow suit.
Crisped, browning edges across sun-hit fronds
Bleached or browning edges spell sun scorch, and it loves to team up with dry soil, hitting hardest on whatever fronds bake in the afternoon light. Slide the plant into deeper shade or throw some cover over it, then soak the soil deeply and pack on mulch to keep that moisture locked in. Snip the worst fronds off and watch fresh ones come charging up to 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 dragging the whole fern down
Yellowing sweeping across the whole plant flags a moisture problem at the roots, and it can swing two ways. Soggy, waterlogged soil drowns the roots, while soil that keeps drying out leaves them gasping, so pin down which way yours goes before you dive in. Dig in some organic matter or lift the fern clear of standing water to get it draining, then lock in a steady routine that keeps the soil evenly moist and the plant comes roaring back.
Fix:
- Improve drainage by adding organic matter or relocating from standing water
- Establish a consistent watering routine to keep soil evenly moist
Fronds ripped and battered where the wind strikes
Strong, drying wind tears into these soft fronds and shreds their edges, and the damage piles up on the side that catches the breeze, with zero spots or pests in sight. Clip off the battered fronds and tuck the plant into a sheltered spot, or build it a quick windbreak. Plant it in a snug, protected woodland corner and the foliage stays whole and handsome.
Fix:
- Remove damaged fronds
- Provide a sheltered planting position or windbreak
Toxicity
Here is the upbeat part: no source confirms this fern is poisonous, and its close relatives like the Boston fern land on the safe-for-pets list. The flip side is that no source confirms this exact species is safe either, so the honest call is that the data isn't in yet. Until it lands, keep pets, livestock, and children from chewing the fronds as a smart precaution.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Caution
Good news first: no source pins this fern as poisonous to cats, and easy cousins like the Boston fern land on the safe list. Even so, a cat that chomps a frond might drool or bring a little back up, so keep it out of reach until the species earns its clearance.
Dogs Caution
Nothing on record says this fern harms dogs, and its shield fern relatives count as non-toxic. A curious dog that gnaws the fronds can still pick up a mild stomach upset, so steer it away and keep things smooth.
Horses Caution
No source calls this fern dangerous to horses one way or the other. Until that gap closes, keep grazing horses clear of it and stay alert for any drooling or dullness if a mouthful goes down.
Rabbits Caution
No toxicity entry covers rabbits and this fern, so its safety stays unproven for them. Offer none of it, and if a frond gets chewed, watch the animal closely.
Livestock Caution
Cattle, goats, and sheep show no documented reaction to this fern, helpful or harmful. Fence it off from grazing stock as a smart precaution instead of betting 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 reliable source jumps in.
People Caution
No part of this fern belongs on a plate, and no source backs it as food. Keep kids from chewing the fronds, and never treat it as a wild edible.
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 show up next to the plain species, each bringing its own spin on color or habit.
'Brilliance'
Its new spring fronds blaze in a brighter, deeper red than the plain species and grip that color further into the season.
var. prolifica
A narrow, finely cut form that throws out little plantlets along the frond stem, handing it a second way to spread all on its own.
How to propagate
The autumn fern is a breeze to multiply, and dividing an established clump is hands-down the fastest way to crank out more.
DivisionEasy
Spring or early autumn · 1 to 2 growing seasons
Division is the fast, fun way to bulk up your stock. Come spring or early autumn, dig up an established clump and pull it into sections, keeping roots and fronds on every piece, then hand the divisions a season or two to root in and fill out. Spores ripening on the frond undersides can raise new plants too, but brace for a much slower haul that calls for serious patience.
Myths
Copper fall foliage is what puts the autumn in autumn fern.
That coppery bronze to orange-red color fires up on the new fronds as they unfurl in spring, then cools into a glossy deep green by summer. The name points to spring, not fall. What actually turns orange-red in autumn is the ripe spores riding the undersides of the fronds.
Each and every fern spells trouble for a cat or dog.
Loads of true ferns in the same family, the Boston fern and sword fern among them, sit on the ASPCA non-toxic list for pets. But no source confirms the status of this exact species, so play it smart and keep pets from chewing the fronds rather than betting it copies its relatives.