Cast Iron Plant
Aspidistra elatior · the Bar Room Plant
It grows on the deep-shade floor of subtropical forests in southern Japan and Taiwan, under a closed canopy where little light reaches. Its tiny flowers open at soil level, hidden under the leaves, so you can keep one for years and never know it bloomed.
Family
Asparagaceae
Origin
East Asia
In the wild
Flowers at soil level
Indoors
0.5–1 m
Growth
Slow
With pets
Safe
Where it's from
Southern Japan and Taiwan
Forest-floor shade
Subtropical island forest, in deep shade beneath the canopy on poor soils.
Outdoors: zones 7–11
Hardier than most houseplants, surviving to about -15°C as a shade ground-cover.
Not invasive
A slow grower, never reported spreading in the wild.
It flowers at the floor
Its small, fleshy, cup-shaped flowers, cream outside and maroon inside, open right at soil level in spring, hidden under the foliage. In the wild they are pollinated by fungus gnats. Indoors it rarely flowers at all, and when it does the bloom is so low and small it is easily missed.
Pollinated by gnats
Research in 2018 found fungus gnats do the work, not larger insects.
An Orwell title plant
It is the title plant of George Orwell's 1936 novel Keep the Aspidistra Flying.
Built to be ignored
Deep shade, dry air, drafts and erratic watering, it shrugs them all off.
How to keep it
LightPart to deep shade
Tolerates a dim corner that kills most plants. Direct sun bleaches the leaves.
WaterLet the top dry
Water regularly in summer, less in winter. Overwatering and root rot is the main risk.
HumidityDry air is fineUndemanding, no misting needed.
TemperatureRoom temperatureWide tolerance, and it survives cool, drafty spots.
SoilAny well-draining mixTolerates clay, loam or sand, acid to alkaline.
FeedingLight, in summerA slow grower that needs very little feed.
DifficultyEasiest there isThe Victorian parlour plant that thrives on neglect.
With petsSafeNon-toxic to cats, dogs and horses per the ASPCA. One of the few easy pet-safe plants.
PropagationDivisionSplit the rhizome in spring. It does not come true from leaf cuttings.
RepottingEvery 3–5 yearsIt resents disturbance and is happy left snug for years.
What the data says
What it costs
A common, inexpensive plant in plain green. Only the slow-to-divide variegated forms cost more.
$15–40
Variegated and speckled cultivars run $40–100 or higher, because variegation plus very slow division keeps them rare.
The clean-air myth
Drag the slider. See how many cast iron plants it takes to clean one room's air.
1 Cast Iron Plant cleans 0.1% of one room's air
You would need many hundreds to make a measurable dent. The famous 1989 NASA result came from a sealed lab box; a real room's airflow beats any plant. Keep it for the dark-corner toughness.
IUCN · Not assessed
In the wild
The houseplant is everywhere, while its wild genus is full of rare, little-studied species.
Aspidistra elatior itself is not assessed on the IUCN Red List. But the genus is a hotspot of narrowly endemic species, many only recently described and under pressure from habitat loss. Ubiquitous in the parlour, patchy in the wild.
When it sulks
Bleached or scorched leavesToo much direct sun. Move it back into shade.
Yellow, mushy baseOverwatering and root rot, by far the most common cause.
No new growthNormal. It is a very slow grower; do not over-feed.
PestsMealybugs, scale, spider mites and thrips. Wipe the leaves, treat early.
Varieties & company
The varieties
VariegataMilky WayAsahiLennon's SongHoshi-zora
Pairs with · keep apart from
FernsPeace LilyCalatheaCactiSucculentsSnake Plant
A new plant, every week.
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