How to Grow and Care for Cast Iron Plants

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.

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!

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.

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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