Cast iron plant
Aspidistra elatior · Asparagaceae
Tall, leathery, dark green leaves rise straight from the ground and survive deep shade, drought and neglect, hence the name. Evergreen in mild-winter regions.
- Size
- 24 in tall, 24 in wide
- Zones
- 7 to 11
- Light
- Part shade to shade
- Flowers
- Grown for its leaves
- Pets
- No toxicity recorded
- Job in a bed
- Drift
A bed built around cast iron plant
The planner designed this bed around cast iron plant when this page was made: a 12 × 6 ft (3.7 × 1.8 m) English border in zone 7, part shade. It chose the other plants from the 535 that suit those conditions, and says below why cast iron plant stands where it does.
The plants
- 1 Cast iron plant × 1, dark green leaves
- 2 Green-and-gold × 16, yellow
- 3 Moor grass 'Greenlee' × 6, tan
- 4 Cardinal flower × 3, red
- 5 Tall astilbe 'Superba' × 4, purple
- 6 Mountain hydrangea 'Tuff Stuff' × 1, pink
- 7 Snowdrop × 10, white
- 8 Striped squill × 12, blue
Why this plant
- The only plant grown for its leaves. Leaf lasts all season, where a flower lasts a few weeks.
- The only bold leaves here. The rest are medium and fine. A change of leaf keeps plants distinct when nothing is in flower.
Why here
- In the middle. At 24 in it is the step between moor grass 'Greenlee' (12 in) in front and mountain hydrangea 'Tuff Stuff' (2½ ft) behind: each is seen over the one before.
- One plant. Three or more is usual for a plant of this kind, and reads better.
- Bold leaf against fine. Moor grass 'Greenlee' is beside it: the strongest contrast of leaf there is.
Why now
- Here for its leaves, all year. They cover the 11 weeks between early March and late November when nothing on the plan is in flower.
- The only leaves in winter. From November to March it is what there is to look at.
Planned as an English border: 4 of the 5 groups (80%) are drifts, longer along the bed than they are deep. Green-and-gold is planted in four places along the bed, which gives it rhythm. Green-and-gold is the plant there is most of: 16 of the 53.
The planner's own design check: 13 Excellent, 2 Good, 2 Satisfactory. It flags one thing to watch: Nothing on this plan is highly poisonous or an aggressive spreader.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where cast iron plant goes in a border
At 24 in it belongs in the middle of a bed. In the planner's ten height classes it is medium short (18 to 24 in).
Its job: drift. Planted in a small group of three or five, and repeated further along in the other number.
The answer to the darkest, driest shade in warm regions, where almost nothing else stays presentable. The upright, strappy leaves contrast well with ferns and mondo grass.
- Deep, dry shade under trees in the South
- Evergreen groundcover
- Narrow beds against north walls
What to plant with cast iron plant
Plants recorded as good partners for it, and what each pairing does:
- Japanese holly fern.
- Mondo grass: fine leaves against its bold ones; low enough (8 in) to stand in front of it.
- Autumn fern: medium leaves against its bold ones.
Questions about cast iron plant
Does cast iron plant need sun or shade?
Cast iron plant grows in part shade (2 to 4 hours of sun, mostly in the morning) and shade (less than 2 hours of direct sun, or bright dappled light). It is one of the few that also put up with deep shade.
It wants ordinary well-drained soil, of average fertility, and a good soak in dry spells.
What zones does cast iron plant grow in?
USDA zones 7 to 11. It is hardy to zone 7, which means it survives winter nights down to about 10 °F (−12 °C).
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
How far apart should cast iron plant be planted?
18 in (45 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 24 in (60 cm), so a group knits into one patch.
It grows 24 in (60 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many cast iron plant plants do I need?
At 18 in apart, set out in staggered rows:
- 5 to fill 10 square feet (about 1 m²)
- 7 for a single row 10 ft (3 m) long
- 17 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as a group of three or five, with a second group further along in the other number.
In the bed above, the planner used one in one group.
Is cast iron plant poisonous to dogs and cats?
No toxicity is recorded for dogs, cats, horses or people, according to NC State Extension and the ASPCA.
"Not toxic" is not "edible": a pet that eats a lot of any plant can be sick.
Is there a native plant like cast iron plant?
Cast iron plant comes from Japan. These North American natives come closest to doing its job:
- Marginal wood fern: the same job in a bed and the same size; medium leaves, not bold.
- Christmas fern: the same job in a bed; 4 in shorter, medium leaves, not bold.
Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.
Do deer eat cast iron plant?
Mostly not. NC State lists it as resistant to deer and rabbits. No plant is proof against a hungry deer in a hard winter, but this one is low on the menu.
What does cast iron plant look like in winter?
Cast iron plant keeps its dark green leaves all winter, so it is one of the plants that hold a bed together from November to March, when the perennials have gone.
In these guides
Every fact on record
- Type
- Perennial
- Size
- 24 in (60 cm) tall, 24 in (60 cm) wide
- Plant
- 18 in (45 cm) apart
- Height class
- Medium short (18 to 24 in)
- Place in the bed
- Middle
- Flowers
- None: grown for its foliage
- Leaves
- Bold texture, evergreen; dark green
- Shape
- Upright, clumping
- Hardy in
- USDA zones 7 to 11
- Light
- Part shade, shade
- Soil
- Average, well-drained
- Water
- Moderate
- Feeding
- Light, in spring
- Family
- Asparagaceae
- Comes from
- Japan
- Stands up to
- Deer, rabbits, salt, poor soil, deep shade
Checked against NC State Extension and ASPCA poison lists. Flowering times are for zone 5: later in colder zones, earlier in warmer ones. Toxicity and spread information is a general gardening guide, not veterinary or medical advice, and invasive status varies by region. If a person or pet eats a plant, contact poison control or a vet. Check your local invasive species list before planting anything with a spread warning.