Oak fern
Gymnocarpium dryopteris
Also called Gymnocarpium and Western oak fern
Garden plant · Ferns & palmsA ground cover rather than a specimen — six inches tall, running gently through leaf mould in deep shade where almost nothing else will. It goes completely dormant in winter, so mark where it is before you dig.
Care at a glance
- Ease
- Medium
- Water
- Every 3 daysWater the ground — water at the base, in the morning, not over the leaves.
- Light
- Full shade
- Feed
- Not needed
- Humidity
- High
- Hardiness
- Very hardy RHS H7, to -25°C
- Size
- 0.2 m tall · 0.5 m across
- Lifecycle
- Perennial
- Origin
- Northern Europe, Asia and North America
Is it safe for pets and people?
No animal-poison authority lists this plant either way.
Nobody has checked this one against a source for us yet, so treat it as unknown rather than safe.
Neither authority names Gymnocarpium. That is an absence and not a clean bill.
Checked against ASPCA and RHS on 2026-09-22. Where a source says nothing, we say nothing.
A guide, not veterinary or medical advice. If a pet or a person has eaten a plant and you are worried, call your vet or doctor now — don’t wait for signs to appear. Spotted a mistake? Tell us.
First signs of trouble
- Bare soil in spring where a colony was. It dies back completely and is only six inches tall in leaf, so it is easy to lose track of — mark it in autumn.Dug up while dormant · disorder
- Fronds bleaching and browning by midsummer in a spot that gets a few hours of direct light. This one wants full shade, which is more than most of the ferns beside it.Scorched in sun · disorder