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How to Care for Cast Iron Plants

Cast Iron Plant

Aspidistra elatior or cast-iron-plant or bar room plant with spotted leaves in pot.

Photo Credit
mizy
Botanical Name
Aspidistra elatior
Plant Type
Houseplant
Sun Exposure
Shade
Soil pH
Varies
Hardiness Zone
8
9
10
11
Special Features
Deer-resistant

Learn how to Plant, Grow, and Care for Cast Iron Plants

Andy Wilcox
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Impressively large, deep green leaves and an upright habit make the Cast Iron Plant a lovely foliage addition to outdoor beds and is a popular houseplant for indoors. Learn how to plant, grow, and care for cast iron plants (and find out why they have this unique name!).

About Cast Iron Plants 

Cast iron plants are grown as foliage both indoors and outdoors. They’re tall enough to use as a backdrop to showcase short flowering plants in a bed and spread slowly by rhizomes. When grown in USDA hardiness zones 7 to 11, they are evergreen perennials that can tolerate quite a bit of shade. 

As you may imagine from their common name, cast iron plants are pretty tough customers. They’ll tolerate some neglect without giving you sass about it (I’m looking at you here, fiddleleaf fig). You won’t need a perfected watering schedule, precise fertilization regimen, or perfect light levels. When grown outdoors, they need very little maintenance. Even as houseplants, they are “hard to kill.” 

Cast iron plants, botanical name Aspidistra elatior, are native to temperate areas of Asia. They look fantastic in a mass planting, providing tall and broad green color in shadier areas of the garden beds that can be hard to work with. Many cultivars are available with spotted, striped, or frosted leaves.

When grown outside, the leaves on many cultivars may reach four inches wide and twenty-four inches tall. Pointy leaf tips and a broad but long shape give the impression of spears of leaves sticking out of the ground. These plants are great for adding ground cover and greenery to shady fences, wooded areas, or foundation lines.

cast iron plant
Green cast iron leaves grow well under the shade of a tree and provide groundcover. Credit: cctm

Why Are They Called Cast Iron Plants? 

Don’t forget to season your cast iron … plant? What a strange name with an interesting history from Victorian times. 

As described by Dr. Lew Feldman, garden director at the UC Botanical Garden at Berkeley, “After gas lighting was introduced to illuminate homes in the late 19th century, Aspidistra was often the only plant that could be grown successfully indoors. This lead to the descriptor, “cast-iron” plant, meaning that it was very hardy. 

But what’s the basis for this hardiness?  Learn more!

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Planting

These tall foliage superstars are not picky about soil and will grow in sandy, loamy, and clayey soils. They do need good drainage and will suffer in consistently wet locations. Cast iron plants are not picky about soil pH and will grow in most conditions.

When planting outside, cast iron plants do best in dappled sun to light shade; although they will grow in deeper shade, growth will be slower. These plants also do well in the dry soils found under conifers and evergreen broadleaf trees like live oaks.

When to Plant Cast Iron Plants

Cast iron plants can be transplanted outside any time during the year in zones 8 to 11. However, like many plants, they will do best if planted in the springtime, allowing them to take advantage of the natural growth period of spring, summer, and fall. 

How to Plant Cast Iron Plants

Cast iron plants should be spaced about a foot apart in an outdoor setting. They’re typically purchased as young potted plants at garden centers and big box stores and are often clearance marked at the end of spring. Full-sized plants can be purchased at many greenhouses. Watch for sales!

When planting outdoors:

  • Amend the soil by adding a scoop or two of compost.
  • Dig a hole about as deep as the rootball and twice as wide.
  • Remove the cast iron plant from the pot and loosen any potbound or girdling roots. To improve rooting growth, you may need to score the edge of the rootball in several locations.
  • Place the plant in the hole and test-fit for depth. The plant should sit at the same level in the ground as in the pot.
  • Refill the hole with the native soil excavated, pressing lightly but firmly to remove any air pockets.
  • Water deeply and apply mulch to keep weeds down.

Cast iron houseplants can be repotted like other houseplants when you bring them home or when they’ve outgrown their current container. Choose a new pot with good drainage, about one size larger than the existing pot. Use any high-quality potting mix. 

To grow cast iron plants indoors, choose a spot with indirect light. Don’t place it right up in the window–save that for other plants. Remember, in their native habitat, these plants are found on forest floors where they receive a dappled light all day long but never the full blast of the sun.

Growing

Cast iron plants earned their name and won’t need much help from you to do their thing. They are one of the easiest houseplants to grow and do quite well, left to their own devices, when planted outdoors as well. 

Follow these care tips for the best results.

  • Provide indirect light. Direct sunlight can scorch leaves. A spot near a window, but not directly in the sunlight, is perfect.
  • When planting outdoors, compost top-dressed annually will provide enough fertility for cast iron plants. For those grown indoors, offer a general-purpose houseplant fertilizer throughout the spring and summer. 
  • Water containerized plants when the soil begins to dry but before it completely loses moisture. 
  • During the first year, water outdoor cast iron plants when the soil feels dry an inch below the surface. After they’re established, they won’t need supplemental watering in most climates.
cast iron plant
Aspidistra elatior foliage. Credit: Simona Pavan

Propagating

Cast iron plants spread slowly via rhizomes underground, but you may wish to speed up the process or move one to a new location. Propagate cast iron plants by dividing the root clump like other perennials.

  • Carefully dig up the cast iron plant and brush away the excess soil so you can see.
  • Using a soil knife or pruners, cut the rootball into several pieces, each with some rhizome and a couple of leaves.
  • Either replant these sections as new plants following the directions above, plant them in pots to care for them while they establish (and you find a spot for them), or give them away as gifts.

Tip: Newly divided baby cast iron plants will need more care and watering while they are established. They won’t earn their cast iron name until they’ve rooted and started growing independently. Then, you can go back to minimal care routines.

Types

All varieties of cast iron plants are low-maintenance, upright, and have gorgeous foliage. You can’t pick a bad one. The differences are mostly in the leaf color patterns. 

  • ‘Variegata’ brings a classical look, with pale, cream-colored striations running lengthwise on deep green foliage.
  • ‘Big Spotty’ has beautiful freckles of pale yellow, akin to paint splatters from shaking a brush.
  • ‘Goldfeather’ has light green to yellow stripes running the length of the leaves. 
  • ‘Asahi’ brings white leaf tips and edges to break up the sea of green foliage.
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Wit and Wisdom

  • With their tough leaves, cast iron plants are much more deer-resistant than hostas for shady spots in your beds.
  • When grown as a houseplant, the large leaves can accumulate quite a layer of dust. Wipe them down with a soft, wet cloth now and then.
  • Cut ragged, yellowing, or unsightly leaves down to ground level to keep the plant lush.

Pests/Diseases

About The Author

Andy Wilcox

Andy Wilcox is a flower farmer and master gardener with a passion for soil health, small producers, forestry, and horticulture. Read More from Andy Wilcox
 

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