Aspidistra elatior is such a popular houseplant that songs have been written about it, and in Victorian times anyone who was anyone had at least one in their parlor.
But cast-iron plants are every bit as tough, adaptable, and attractive when they are grown outdoors in the garden.
This species earned its common name because they are pretty much as tough as cast iron. Tolerant and able to thrive in shade, drought, and depleted soil, there’s pretty much nothing that can destroy these robust specimens.
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Hardy to USDA Zones 7 to 11, cast-iron plants bring life and color to bland, shady areas in the landscape.
They can also be grown in containers in colder zones and brought indoors for the winter.
If you’re looking for information about growing cast-iron plants indoors, read our guide.
Otherwise, buckle in. Here’s what we’re going to discuss to help you make your outdoor aspidistras thrive.
Indoors or out, growing cast-iron plants is a piece of cake. But before we wax poetic about how easy they are to grow, you might be interested in their origin story.
Let’s talk about that, first.
Cultivation and History
Aspidistra eliator is indigenous to the southern islands of Japan and Taiwan. An herbaceous evergreen, it grows up to three feet tall and wide in the understory of warm, tropical forests.
The long, strappy leaves emerge from underground rhizomes and may be solid green or or have a variety of patterns featuring stripes, spots, or both.
This species was first described by botanist John Bellenden Ker Gawler in 1822. It rapidly gained not just popularity but a true following, it was a bit like the Pokemon of the late 1800s.
Victorians are well known for their passion for houseplants, and cast-iron plants were one of the most sought-after in the mid-1800s.
In the late 19th century, gas lighting was introduced into Victorian homes and A. elatior were among the few houseplants that could survive the ethylene-heavy air that resulted from burning the gas.
Having an Aspidistra in those days symbolized a comfortable, middle-class life. But over time, it became a symbol of the pursuit of money and status, as George Orwell critiqued in his novel “Keep the Aspidistra Flying.”
As a garden specimen, it’s never been quite as popular, but if you want a plant that can liven up shady areas and won’t be turned to lace by snails and slugs (looking at you, hostas), there’s no better option.
If your cast-iron plant is really happy in its location, it will send out funky purple flowers at the base.
The blooms have a fragrance that is earthy, kind of like a mushroom, which is intended to attract fungus gnats (Cordyla sixi and Bradysia spp.) and slugs as pollinators.
Cast-Iron Plant Propagation
That aforementioned strange method of pollination also means that seeds aren’t readily available, so don’t fall for anyone advertising seeds for sale.
Instead, you can either purchase a plant or divide an existing one.
By Division
If you already have cast-iron plants in your landscape, propagation by division is easy.
Find a healthy-looking clump of leaves with a natural division between them and follow them down to the soil.
You’re going to need to dig this section out with a bit of margin around it to ensure that you get a good chunk of the rhizome.
A. elatior has shallow roots, so you don’t need to dig very deep, but you should dig nice and wide. Use a trowel or spade and dig down at least six inches.
All it takes is a bit of roots and rhizome for the plant to survive, but the more you dig up, the better. You can either dig up the entire clump and separate it into multiple sections or simply remove a few stems with the rhizome and roots attached.
Once you have your divisions you can replant them as described below.
Transplanting
This is a plant that doesn’t suffer much from transplant shock. As such, you don’t need any special care to get your potted specimen or division into the ground.
Dig a hole that’s twice as wide and just as deep as the container the cast-iron plant is currently growing in, or in the case of divisions, a bit larger than the root system. You want it to be at the same level it was in the container once it’s in the ground.
Then, gently remove the plant from the container and loosen up the roots. Lower it into the hole, spreading out the roots. Fill in around with soil.
Add some water to the hole and let the soil settle a bit. Add a bit more soil if necessary.
How to Grow Cast-Iron Plants
Cast-iron plants are so difficult to kill that they are featured in a short horror story called “The Man Who Hated Aspidistras” by William Fryer Harvey, about a man who was haunted by a cast-iron plant he couldn’t get rid of.
The character in George Orwell’s novel, “Keep the Aspidistra Flying” tries to kill his specimen by burning it with cigarette butts, but it still won’t die.
These plants have earned quite a reputation for being indestructible. They aren’t quite that tough, but it’s not an exaggeration to say that they’re pretty resilient.
Anything from partial sun to full shade is fine for aspidistras. Dappled shade or partial shade is ideal, but they will adapt.
Your cast-iron plant will probably even survive in full sun, but the leaves will likely end up burned, and they won’t grow as lush and beautiful as they would in a more hospitable location.
Cast-iron plants prefer consistently moist soil, though you can let the surface of the soil dry out between waterings.
If you water your garden using municipal water, be aware that they are a bit sensitive to fluoride, so if your municipality adds fluoride, consider collecting rainwater instead.
They can tolerate high heat, some drought, and depleted soil. They will even survive temperatures dipping down to 18°F.
Ideally, give them loose, loamy soil, with a pH of 6.5 to 7.5, though the plants will tolerate some clay or sand. The only hard and fast requirement is that the soil must be well-draining.
Highly variegated types with lots of white or yellow on the foliage can be a little less forgiving, however.
You can keep the plant in a gallon-sized or larger container, though you’ll eventually need to upgrade to a three-gallon size. Once you reach three gallons, keep it in that size for the rest of its life.
Use any clean, new potting soil that you prefer. Don’t reuse potting soil because it can become depleted or harbor pathogens. The only requirement is that the container has adequate drainage.
Something like Tank’s-Pro Potting Mix, made from organic compost and coconut coir would work well, but use whatever works for you.
Tank’s-Pro Potting Mix
Arbico Organics carries this excellent mixture in one-and-a-half-cubic-foot bags.
Cast-iron plants can and will spread around the garden if you let them. They won’t become invasive, but wherever the light is right, they will spread.
That can be a plus or a minus, depending on your goals. For areas that need erosion control or a ground cover, they’re perfect.
Growing Tips
- Grow in partial sun, partial shade, or dappled shade.
- Provide consistently moist soil.
- Try to irrigate with rainwater as they are sensitive to fluoride in municipal water.
Maintenance
Feed once a year in the spring and again in the fall with a mild, balanced fertilizer.
There’s no need to prune them, but remove any dead, diseased, or broken leaves as you see them. Remove older leaves as they age and turn yellow.
If you live in Zone 7, you’ll need to protect the plant from cold winter winds to prevent freeze damage. Speaking of, you can get away with growing aspidistras in Zone 6 if you situate them next to a south-facing brick or cement wall.
Alternatively, grow your cast-iron plants in pots and bring them indoors during the winter months.
Aspidistra Cultivars to Select
In general, heavily variegated types are less tolerant of poor soil, bright sun, or too little light.
The species plant is the classic that earned the respect and love of so many people over the years, with its sturdy, solid green leaves.
Cast-Iron Plant
You can grab a live specimen in a gallon or three-gallon container at Fast Growing Trees.
There are a variety of different cultivars such as ‘Snow Cap,’ with its white-tipped leaves is a fun option if you want some contrast.
‘Small n’ Smart’ is a bit more petite, with narrow, strappy leaves for a grass-like appearance.
’Asahi’ is one of my favorites with ombre white stripes down the centers of the leaves. ‘Ippin’ always draws attention with its varying stripes of white, cream, and light green.
’Stars ‘n Stripes’ has both spots and stripes, while ‘Nagoya Stars’ is a favorite for those who want the speckled look.
Managing Pests and Disease
For those grown in full shade, you might notice white or green splotches on the leaves.
If these can be wiped off, it’s likely just pollen gathering or lichen growing. Neither of these is a problem and you can safely ignore them or just wipe them off if you don’t like the look.
Don’t use horticultural oils on cast-iron plants unless you’re absolutely desperate. It won’t kill them, but it causes dark green, water-soaked spots that are ugly.
Insects
Snails and slugs will eat aspidistras, but it’s not their favorite fare. Look for ragged edges on the leaves and if you see them, read our guide to learn how to deal with these pests.
Scale
Fern scale (Pinnaspis aspidistrae) is perhaps the most common pest to infest cast-iron plants. The adult males are small and white, while the females are brown.
Both look like little bumps on the stems and undersides of the leaves, and they sometimes appear on the top surface of the foliage.
Scale insects have a hard shell and use their sucking mouthparts to consume the sap from the plant.
This feeding causes yellowing and stippling of the foliage, and stunted growth.
They can be removed by gently scraping them off with a fingernail or butterknife and drowning them in soapy water.
You can read more about scale insects and how to manage them in our guide.
Spider Mites
Two-spotted spider mites (Tetranychus spp.) aren’t extremely common, but they will feed on plants that are dry or in hot areas.
They usually hide on the undersides of the leaves and use their sucking mouthparts to draw out that sweet, sweet sap.
When they’re present, you won’t notice any symptoms at first, but as the populations build up, the leaves will take on yellow stippling, and eventually, the tips will die back.
The best way to get rid of these pests is to spray the leaves with a gentle stream of water to knock them off. Do this every other day for several weeks.
Learn more about how to deal with spider mites in our guide.
Disease
The chances of running into a fungal problem are low, but if you do, it will probably be Fusarium.
When Fusarium pathogens are present in the soil, they cause water-soaked spots that mature into tan or reddish-brown lesions with a yellow halo. These typically appear on younger leaves first.
The specific pathogen Fusarium solani causes the leaves to rot at the base rather than causing leaf spots. Underground, the roots turn black and mushy.
In either case, you can generally avoid it by not overwatering and by watering at the soil level rather than on the foliage.
You should also space them far enough apart to provide adequate air circulation. Poor drainage can also contribute to the disease.
If you notice any of the above symptoms, you’re going to want to deploy a fungicide that contains Bacillus subtilis or a product that uses the spores of Streptomyces Strain K61 for fungal control.
Mycostop BioFungicide
Mycostop contains this naturally occurring bacterium, which is derived from sphagnum moss. Grab a five or 25-gram packet at Arbico Organics.
Following the manufacturer’s directions, apply the product to the leaves and soil once every two weeks until new, healthy growth develops.
Best Uses for Cast-Iron Plants
Cast-iron plants are perfect as ground cover for shady areas, but they can also be used as accents, borders, edging, or in mass plantings.
They’re also perfectly polite in containers, whether to add some height to a mixed planting or fill a pot.
The leaves are popular in floral arrangements as filler and linear accents.
Quick Reference Growing Guide
| Plant Type: | Herbaceous evergreen perennial | Flower/Foliage Color: | Purple/green, green with yellow, green with white |
| Native to: | Japan, Taiwan | Water Needs: | Moderate |
| Hardiness (USDA Zone): | 7-11 | Tolerance: | Drought, low humidity, shade, pollution |
| Exposure: | Partial sun, partial shade, dappled shade | Maintenance: | Low |
| Time to Maturity: | 1 years | Soil Type: | Loose, rich, loamy |
| Planting Depth: | 1-inch (rhizomes), same depth as container (transplants) | Soil pH: | 6.5-7.5 |
| Height: | 3 feet | Soil Drainage: | Well-draining |
| Spread: | 3 feet | Family: | Asparagaceae |
| Growth Rate: | Moderate | Genus: | Aspidistra |
| Common Pests and Diseases: | Scale, snails and slugs, spider mites; Fusarium wilt | Species: | Elatior |
Get Cooking With Cast Iron… Plants
Even if they were kind of ugly, I’d probably still grow A. elatior.
They’re so easygoing and provide color and texture in areas that most other plants refuse to even consider growing.
They’re even more adaptable than hostas, and certainly tougher, if you can believe it!
That’s why I think they’re poised to become much more popular as landscape plants.
Do you grow cast-iron plants outdoors? Are you going to fill a spot under some trees? Line a north-facing walkway? Fill us in on your plans in the comments.
And for more information about growing other houseplants in the landscape, add these guides to your reading list next:
