Ornamental · Dryopteridaceae
Autumn Fern
Dryopteris erythrosora
Settled into moist shade, the autumn fern brings a copper-toned glow to the season's quietest corners.
Partial shade
Every 5–7 days
USDA 5–9
18–30 in · 45–76 cm
Overview
The autumn fern is the kind of woodland plant that gives a shaded garden a sense of composure, valued above all for the copper-red note its new fronds bring to a planting. That warm tone in spring eases into a glossy green as the season turns, and the clump keeps its form through the cold, staying evergreen in milder gardens so a border never reads empty in the off months.
Where it really earns its place is in the easy living it offers. Pair it with shade and a steady watering routine and it slips into the rhythm of a home garden without fuss, and once established it carries on through dry shade and short dry spells better than most ferns. Deer pass it by as well, which makes it a calm anchor for a woodland edge or a shaded path.
There is one consideration worth weighing as the planting takes shape: it travels by underground rhizomes and can claim more ground than first intended. North Carolina Extension flags it as potentially weedy, so a look at regional guidance belongs in the planning stage before it joins the garden.
Care
The short version: part to full shade in rich, humusy soil kept evenly moist. Water it through the first season to settle it in, clear the old fronds in late winter, and from there it keeps its poise on its own.
Light
Give it part to full shade, the soft dappled light of a woodland floor that suits a quiet, sheltered corner. It takes some morning sun, but harsh afternoon light scorches the fronds unless the soil stays reliably moist.
Water
Keep the soil evenly moist, above all through the first growing season while the roots settle into their new home. Watering every 5 to 7 days suits most spots, and once established the fern carries on through short dry spells and dry shade better than most.
Soil
Plant it in humus-rich, well-drained loam generous with organic matter. A slightly acidic pH of 5.0 to 6.5 suits it best, and plenty of leaf mold or compost holds the ground moist without letting it turn soggy.
Temperature
It is hardy and cold-tough, weathering winters down to -20°F (-29°C) and warmth up to around 86°F (30°C). That range covers USDA zones 5 through 9, where it stays evergreen at the milder end.
Humidity
Average humidity around 40% to 70% keeps the fronds looking their best. Like most ferns it dislikes dry air, so a shaded, sheltered position with moist soil does more for it than chasing any single humidity number.
Feeding
This is a light feeder, so a restrained hand serves it well. A spring topdress of compost or leaf mold feeds it nicely, or a balanced slow-release fertilizer applied once as growth begins will do.
Pruning
It asks almost nothing in the way of cutting back. 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 to come.
Repotting
Grown in a container, it wants repotting every 2 to 3 years, or when roots push from the drainage holes and the soil dries out fast. A crowded rhizome lifting at the surface is another sign it is ready for more room.
Size & spacing
Expect 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 when placing it, and keep in mind it can travel further by rhizome over the seasons.
When to plant
With no flowers to time and no harvest to wait on, planting is the single date that shapes how this fern enters a garden. Set it out in spring once the frost has passed, or in early autumn while the soil still holds enough warmth for the roots to settle 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
Almost every concern with this fern reads in the fronds, and most come down to too much sun, too much wind, or a watering routine that has drifted. Let the foliage point the way and the remedy usually falls into place. Match the look below and act before more fronds follow the same path.
Bleached, browning edges on sunlit fronds
Bleached, browning edges are the look of sun scorch, and they tend to arrive when the soil has run dry, showing first on the fronds that sit in the day's hottest light. The fix is to move the plant into a more sheltered, shaded corner of the garden, then water it deeply and lay mulch to keep that moisture in place. Tidy away the worst fronds and the clump soon refreshes itself.
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
Yellowed fronds and a clump losing its vigor
When yellowing spreads across the whole clump, the trouble is a moisture problem at the roots, pulling from one of two directions. Waterlogged ground leaves the roots drowning, while soil left to dry out leaves them wanting, so read which way the planting leans before stepping in. Improve the drainage with organic matter or lift the fern clear of standing water, then keep to an even, unhurried watering rhythm that holds the soil reliably moist.
Fix:
- Improve drainage by adding organic matter or relocating from standing water
- Establish a consistent watering routine to keep soil evenly moist
Fronds frayed and tattered by wind exposure
Strong, drying wind is the enemy of an elegant clump, fraying the fronds along their edges on whichever side meets the breeze, with no spotting or pests in the picture. Clear away the battered fronds and give the plant a more sheltered position, or set a screen to break the gusts. A quiet, protected corner of the garden keeps the foliage poised and intact.
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 hold a safe listing for pets, which sets a reassuring tone. Yet no source confirms this exact species is safe either, so the honest position is that the data isn't settled. Until it is, keep pets, livestock, and children from chewing the fronds as a sensible precaution.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Caution
No source names this fern as poisonous to cats, and its refined relatives like the Boston fern carry a safe listing. Even so, a cat that nibbles a frond may drool or bring a little back up, so keep the planting out of a cat's reach until the species is cleared.
Dogs Caution
Nothing on record marks this fern as harmful to dogs, and its shield fern relatives are counted non-toxic. A curious dog that chews the fronds could still come away with a mild upset, which is reason enough to steer it elsewhere.
Horses Caution
No source settles whether this fern poses a risk to horses either way. Lacking that confirmation, keep grazing horses away from the planting and watch for drooling or dullness if any is eaten.
Rabbits Caution
Rabbits sit outside any toxicity entry for this fern, leaving its safety unproven for them. Offer none of it, and treat a chewed frond as a cue to keep an eye on the animal.
Livestock Caution
Cattle, goats, and sheep have no recorded response to this fern, helpful or otherwise. Fence the planting off from grazing stock as a precaution rather than assuming it is fine.
Birds Caution
Nothing on record speaks to how birds handle this fern. Keep pet and backyard birds away from the fronds until a reliable source has its say.
People Caution
No part of this fern belongs on the table, and no source vouches for it as food. Keep children from chewing the fronds, and never mistake it for 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 sit alongside the plain species, each offering its own variation on color or habit for a planting.
'Brilliance'
Its new spring fronds arrive in a brighter, deeper red than the plain species and hold that color further into the season.
var. prolifica
A narrow, finely cut form that raises little plantlets along the frond stem, giving it a second way to spread on its own.
How to propagate
The autumn fern asks little to multiply, and dividing an established clump is by far the quickest way to carry it into new corners of a garden.
DivisionEasy
Spring or early autumn · 1 to 2 growing seasons
Division is the simplest way to make more. In spring or early autumn, lift an established clump and ease it into sections, leaving roots and fronds on each piece, then give the divisions a season or two to settle and fill out their place. New plants can also be raised from the spores ripening on the frond undersides, though that route runs much slower and asks for more patience.
Myths
The autumn label celebrates fronds that blush copper as the season turns to fall.
The coppery bronze to orange-red color belongs to the new fronds as they unfurl in spring, and it settles into a glossy deep green by summer. The name speaks to spring, not fall. What does turn orange-red come autumn is the ripe spores on the undersides of the fronds.
No fern is safe to keep around cats or dogs.
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 wise move is to keep pets from chewing the fronds rather than assume it follows its relatives.