Houseplant · Asparagaceae
Cast Iron Plant
Aspidistra elatior
Tuck it into the darkest corner of the house and the cast iron plant just keeps going.
Low light
50–68°F · 10–20°C
USDA 7–11
1–3 ft · 0.3–0.9 m
Overview
The cast iron plant earns its name. It puts up with low light, dry air, missed waterings, and a wide swing in temperature, which is why Victorian parlors were full of it and why it still suits a dim hallway or a forgotten corner today. It is a slow growing evergreen from the lily-of-the-valley side of the asparagus family, native to the woodland floor of southern Japan.
What you get is a clump of upright, leathery dark green leaves that rise straight from the soil, each one long, glossy, and tough enough to ignore most of what kills fussier houseplants. There is no showy flower to wait for. The plant does bloom, but the small cup-shaped flowers sit right at soil level and are easy to miss, so this is grown for its foliage and its patience.
Best of all for a home with animals, the cast iron plant is non-toxic and pet-safe. The ASPCA lists it as safe for cats, dogs, and horses, so you can set it where a curious nose will reach it without a second thought.
Care
The short version: give it low to medium indirect light, well drained soil, and a drink only once the top few inches dry out, then mostly leave it alone.
Light
Low light is where this plant shines, and it handles deep shade through to bright indirect light with ease. The one thing to avoid is direct sun, which bleaches and scorches the leaves. A north-facing window or a shady corner suits it perfectly.
Water
Let the soil dry down 2 to 3 inches (about 5 to 8 cm) before you water again, then water until it drains freely and never leave the pot sitting in a saucer of water. Cut back further in winter while the plant rests. Soggy soil is the single biggest cause of root rot, so erring on the dry side is safer.
Soil
Plant in a rich, well drained potting mix with some peat in it. It will cope with sandy, loamy, or clay soils, but it will not forgive soil that stays wet, so drainage is what matters most.
Temperature
Ordinary room warmth suits it, with a comfortable range of 50°F to 68°F (10°C to 20°C). It tolerates cooler spells better than most houseplants but should be kept clear of hard frost.
Humidity
This plant is happy in low humidity and asks for nothing special, which is part of why it survives so well indoors. Dry household air that troubles other plants does not bother it.
Feeding
Feed sparingly with a general houseplant fertilizer about once a month from spring to late summer, then stop for the rest of the year. Variegated forms want even leaner treatment, since rich soil washes out their markings.
Pruning
Pruning is almost nothing here. Just snip off any damaged, yellowed, or scorched leaves at the base as they appear to keep the clump looking fresh.
Repotting
Being slow growing, it can sit in the same pot for several years and only needs moving up one size when roots start poking through the drainage holes. It actually prefers being a little snug.
Size & spacing
A mature clump reaches about 1 to 3 feet (30 to 91 cm) tall and spreads 12 to 24 inches (30 to 61 cm) wide, growing slowly enough that it holds its shape for years.
Troubleshooting
This is a hard plant to harm, so problems are few and almost always trace back to too much sun or too much water. Read the early signs on the leaves and you can fix things before they spread. Match what you see below, then act.
Yellowing leaves and a soft, mushy base
Soggy soil leads to root rot, the most common way this otherwise tough plant gets killed. The base softens, the roots turn brown and mushy, and the trouble traces back to standing water in the saucer. Stop watering and let the mix dry, then unpot the plant, cut away the rotten roots, and repot in fresh well drained mix.
Fix:
- Stop watering and let the soil dry out
- Unpot, cut away rotten roots, and repot in fresh well-drained mix
- Discard standing water from the saucer
Stippled leaves, fine webbing, or sticky bumps
Stippling and fine webbing point to spider mites, which thrive in warm, dry air, while immobile tan bumps mean scale and white cottony masses mean mealybugs. Wipe the leaves down and pick off what you can see, then treat with insecticidal soap or horticultural oil. Keep the plant away from the rest of your collection until the pests are gone.
Fix:
- Wipe leaves and remove visible pests
- Treat with an appropriate insecticidal soap or horticultural oil
- Isolate the plant until the infestation is controlled
Pale, bleached patches or scorched brown leaves
This is sun scorch, and it is the one thing the cast iron plant won't shrug off. Direct sun bleaches and burns the leaves, usually after a move to a brighter spot. Shift it back into filtered light or shade and cut the worst leaves off at the base.
Fix:
- Move the plant out of direct sun to a low-light, filtered, or shaded position
- Remove badly scorched leaves at the base
Brown tips and edges on otherwise green leaves
Brown tips usually mean a buildup of fertilizer salts in the soil, though long spells of bone dry soil can do it too. Stop feeding and flush the pot with plenty of plain water to wash the salts out. Trim the brown tips for looks, then go back to light, monthly feeding only in the growing season.
Fix:
- Stop fertilizing and flush the pot with plenty of plain water to leach out salts
- Trim browned tips for appearance
- Resume only light, monthly feeding in the growing season
Variegated leaves fading back to plain green
The cream and white markings fade when a variegated plant sits in rich soil or too little light, and new growth comes in solid green. These cultivars hold their color in lean, nutrient-poor soil, so ease off the feeding. Give them steady, indirect light rather than the deepest shade.
Fix:
- Grow variegated cultivars in lean, nutrient-poor soil and avoid heavy feeding
- Provide adequate (but not direct) light rather than very deep shade
Toxicity
Good news for pet owners and parents: the cast iron plant is non-toxic across the board. The ASPCA lists it as safe for cats, dogs, and horses, and there is nothing harmful in the leaves for other animals or for people either. You can place it anywhere without worrying about a stray nibble.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
The ASPCA lists the cast iron plant as non-toxic to cats, so a curious nibble won't poison them. A mouthful of any tough leaf can still upset a sensitive stomach, but there is nothing here to worry about.
Dogs None
Dogs are in the clear too, since the ASPCA rates this plant non-toxic to dogs. The leathery leaves are not a tempting chew, and no harmful compounds are involved.
Horses None
The ASPCA also clears it for horses, with no toxicity expected. A grazing horse has nothing to fear from the foliage.
Rabbits None
Rabbits face no poisoning from this plant, and it carries no known toxins. The thick leaves are unlikely to draw much interest either way.
Livestock None
Grazing animals such as goats, sheep, and cattle are safe around it. Nothing in the leaves causes the stomach or nerve trouble that toxic plants bring on.
Birds None
Pet birds can share a room with it without risk, as the plant holds no compounds that harm them. A pecked leaf is harmless.
People None
The cast iron plant is safe to have around children, with no poisonous parts. It isn't grown to be eaten, but an accidental taste does no harm.
Varieties
Most cast iron plants are plain glossy green, but a handful of cultivars trade some of that toughness for striped or spotted leaves. These are the ones you are most likely to find.
'Variegata'
Its leathery dark green leaves carry irregular creamy white stripes, but the markings only hold up if you keep it in lean, nutrient-poor soil.
'Milky Way'
Broad lance-shaped dark green leaves are scattered with small white spots that look like flecks of starlight.
'Big Spotty'
A bolder spotted form noted by Clemson, with larger markings across the foliage.
'Goldfeather'
A variegated cultivar documented by UF/IFAS for its patterned leaves.
'Snow Cap'
Another variegated selection recorded by UF/IFAS, prized for its pale markings.
How to propagate
There is one reliable way to make more cast iron plants, and it costs nothing but a little patience.
DivisionEasy
Spring and early summer, while actively growing · Several weeks to a few months (slow)
The cast iron plant is best multiplied by dividing the clump in spring or early summer while it is actively growing. Lift it, tease the matted rhizomes apart, and make sure each new piece carries two or more leaves. Be patient afterward, since the divisions are slow to settle and take anywhere from several weeks to a few months to root in.
Myths
A plant this tough can take direct sun.
It earns the cast iron name by putting up with shade, neglect, and a wide swing in temperature, but direct sun is its weak spot. Strong light bleaches, browns, and scorches the leaves. Keep it in bright indirect light through to deep shade.
It is impossible to kill, so you can water it as much as you like.
It does take drought and on-and-off watering in stride, which is where the reputation comes from. The catch is the other direction. Overwatering and soggy soil cause root rot, and that is the main way the plant actually dies.