Maidenhair fern vs Asparagus fern

Adiantum raddianum · Asparagus setaceus

Pet safety: Maidenhair fern is listed non-toxic to cats and dogs; Asparagus fern is toxic (sapogenins). If the two are sold under the same name, a mislabelled plant is a genuine risk in a house with animals.

Why these two get mixed up

Asparagus fern is recorded here as a pet-safe alternative to Maidenhair fern, so the question is usually whether the swap is actually a fair one.

Maidenhair fern (Adiantum raddianum) — **Maidenhair fern** — Adiantum raddianum. Photograph by Forest & Kim Starr, Wikimedia Commons , CC BY 3.0.

Asparagus fern (Asparagus setaceus) — **Asparagus fern** — Asparagus setaceus. Photograph by Forest & Kim Starr, Wikimedia Commons , CC BY 3.0.

	Maidenhair fern	Asparagus fern
Scientific name	Adiantum raddianum	Asparagus setaceus
Family	Pteridaceae	Asparagaceae
Light floor	Low	Medium
Water	2–5 days	4–9 days
Humidity floor	60%	40%
Mature height	8–18 in	12–36 in
Habit	spreading	spreading
Growth rate	moderate	fast
Difficulty	Difficult	Easy
Toxic to pets	No	Yes
Typical price	$12–30	$10–28

Highlighted cells are where the two actually differ. Everything else they share.

The differences that matter

Pet safety

This is the difference that matters most. Maidenhair fern is listed non-toxic to cats and dogs; Asparagus fern is toxic (sapogenins). If the two are sold under the same name, a mislabelled plant is a genuine risk in a house with animals.

Light

Maidenhair fern tolerates low light; Asparagus fern needs medium as a floor. Put the second in the first's spot and it stretches and declines.

Difficulty

Asparagus fern scores 2 of 5, Maidenhair fern scores 5. it dies from a single dry afternoon and browns below about 60% humidity. Realistically a terrarium or bathroom plant, not a shelf plant.

Humidity

Maidenhair fern wants a floor of 60%; Asparagus fern copes at 40%. In a heated room in winter that gap is the difference between crisp edges and none.

Not even related

Maidenhair fern is Pteridaceae, Asparagus fern is Asparagaceae. They share a shop label and nothing else — different families, different continents, different care.

Which should you buy?

With a cat or dog in the house, take Maidenhair fern. The other is toxic, and if the shop label is wrong you will not know which you have brought home.
In a dim room, take Maidenhair fern.
If you forget to water, take Asparagus fern, which goes 6 days between drinks.
If it is your first plant, take Asparagus fern, at 2 of 5.
For a small shelf, take Maidenhair fern, which stops around 18 inches.

Full entries

Maidenhair fern — care fields with sources, toxicity with every authority consulted, propagation and diagnosis. Asparagus fern — the same.

Sources

This database's own care records for Adiantum raddianum and Asparagus setaceus — every figure compared above.
Royal Botanic Gardens Kew, Plants of the World Online — accepted names and families for Adiantum raddianum and Asparagus setaceus
ASPCA Animal Poison Control — toxicity classification for both, cited on each species entry
Photographs: Wikimedia Commons, individually credited and licensed above

Compiled and edited by Tony Valcarcel · 2026-09-12
Every comparison above is drawn from a recorded field. Where the honest distinguisher is visual we show both photographs rather than describing a leaf we have no field for. How this is sourced.