If you want something easy to grow that doesn’t need much light, we have the plant for you. Cast-iron plants are some of the hardest houseplants to kill and they’re also super tough when growing in your outdoor garden.
Cast-iron plants can survive neglect, low light conditions, and drought, plus they resist pests and diseases.
When it comes to picking the right houseplant, do you prefer something nice and easy? Is it pretty dark in your home? Do you travel a lot and need something low maintenance? You’ll love cast-iron plants.
What Are Cast Iron Plants?
Cast-iron plants (Aspidistra elatior) originally came from Taiwan and the southern islands of Japan where it is commonly found in forested areas. When it comes to the Aspidistra genus, there are 100 species, but most people grow the A. elatior species, but you’ll also see varieties like attenuata, basalis, carnosa, and daibuensis.
Aspidistras have long, glossy green leaves that sometimes have stripes or spots.
Cast-iron plants produce purple flowers when growing in the wild, but when planted indoors they don’t bloom. If you’re fortunate enough to find cast iron plants in the wild and you wait patiently for the blooming season, look at the ground.
That’s where the flowers form. They look like little purple mushrooms growing on the ground and they attract pollinators like fungus gnats. Isn’t nature wild?
If you want to keep your cast iron plant outdoors year-round, you need to be in USDA Growing Zones 7-11. Otherwise, grow it indoors or in a container that you can bring in during the cold weather.
In the past, cast iron plants were seen as a symbol of a successful middle-class life and were found in many Edwardian and Victorian homes. Due to the resilient nature of this plant, it was a popular choice for many homeowners and families.
As with all things, it eventually fell out of favor and was considered to be old-fashioned for a time. Luckily, these tough little wonders are making a real comeback.
There are many exceptional cultivars out there, some with solid leaves, some with stripes, and some with both. There are always new ones popping up on the market, so keep an eye out.
‘Big Spotty’ has slightly crinkled leaves and large, distinct white spots all over the foliage. It’s almost as if the leaves are sparkling in the light.
One of the most popular options out there, the beautiful ‘Milky Way’ has white speckles across the dark green leaves that will remind you of looking up at the beautiful night sky. Grab a four-inch live plant at Amazon.
This is a tough little cultivar that can survive down to Zone 6 if you give it a little protection in the winter. It has beautiful, faintly striped leaves.
Stars and Stripes
As you might suspect, this cultivar has both distinct stripes and spots on the dark green leaves.
‘Rigid Ribbons,’ as you might expect, has long, thin leaves that maintain a fairly rigid growth habit. This is a more tender cultivar that only survives down to Zone 9.
Planting Cast Iron Plants
You can’t plant aspidistras from seed unless you have flowering plants with lots of pollinators on your property. Most of us don’t. So you either need to divide from an existing plant or buy a transplant.
The first stage in planting is finding the right soil. Thankfully, these plants can tolerate a variety of soils but they must have good drainage. The ideal soil is rich, loamy, and slightly acidic. Outdoors, they can grow in sandy or clay soils, but to give them the perfect conditions, work in plenty of well-rotted manure or compost.
If you plan on growing cast iron plants in containers, a general potting mix will do the trick. Always use a container with drainage. These plants can’t stand wet feet.
Wherever you grow them, they should be out of direct sunlight. Anywhere from deep shade to dappled shade will do.
To take a division, dig out a clump of an existing plant using a shovel. Take at least two leaves with ample roots attached for the propagation to be successful.
Once you’ve taken the leaves you can plant them in a fresh container with potting mix or directly into the ground.
You should be cautious with young plants as they need more consistent water, but you want to avoid providing too much water as this will lead to root rot. Try to keep the soil feeling like a well wrung-out sponge.
How to Care For Your Cast Iron Plant
Now for the easy part. Caring for these plants is pretty much foolproof.
Despite the fact that cast-iron plants can survive in drought-like conditions, that doesn’t mean that they should live without moisture.
Ideally, you want to keep the soil moderately moist at all times.
After the plant has established itself for a year or so, wait until the top inch of soil is dry before watering again. The easiest way to tell that the soil is dry is by placing your finger into the soil and checking to see if there is any moisture. If it’s dry to your first knuckle, add water.
Houseplants or container plants need more water than those in the ground. During winter and fall, you don’t need to fertilize this plant. It’s only necessary during the spring and summer growing season. When you fertilize, you should water it first to avoid burning the roots during the process.
Use an all-purpose liquid fertilizer and dilute it in half.
Outdoors, fertilize once a year in the spring with a foliage-targeted fertilizer.
As long as they aren’t being hit by direct sunlight, they should be happy. While they may grow slower if you place them in a dark corner of the basement, they’ll still survive.
Ideally, place them in bright, indirect sunlight. Outdoors, under trees, or on the north side of your home is perfect. Anywhere a hosta will grow, a cast-iron plant will grow.
The exception is if you live in a mild climate like the coast of the Pacific Northwest. They can handle some direct light in areas like this. If the leaves are exposed to intense light they’ll become bleached and burned.
Here’s a quick summary:
- If you’re growing cast iron plants outside, place them in a shaded area with indirect or dappled sunlight.
- Indoors you should place them in bright, indirect light. Having said that, they can survive even if they are in full shade. They just might not grow as big and bushy.
Temperature and Humidity
Next on the list of growing requirements for cast iron plants are temperature and humidity. The best temperature for these plants is between 60-75℉, and they go dormant under 50°F. If the temperature falls below 35℉ then your plant will likely die.
If you live below Zone 7 and you want to have your aspidistra outside, grow it in a container and bring it indoors during the winter.
In terms of humidity levels, the humidity in your home is likely just fine. In extremely dry areas, you can add a little humidity if you want by using humidity trays or humidifiers. Don’t stress it too much, though. These plants are extremely tolerant of dry conditions.
How can you tell if your plant needs to be repotted? The most obvious sign is when the roots start growing out of the drainage hole or circling the surface of the soil. With cast iron plants, this will might not happen for several years.
At that point, you’ll need to divide them or put them in a bigger container.
The best time to repot or divide your plant is in spring when the plant is just emerging from dormancy.
To divide, remove the plant from its container, split it in half, and place one half in a new pot and one half in the old one. To repot, remove from the old pot, knock away the loose dirt, and place in a new container that is one size up.
Common Pests and Diseases
Even though cast iron plants are not known for being vulnerable to pests and diseases, it’s good to know in advance what could happen so you’re prepared.
Overall, the only pests you should be worried about are the common houseplant pests such as mites and scale.
You should also keep an eye out for aphids. You can spot aphids by the appearance of small brown, white, and yellow spots on the leaves. Also look for ants or the sticky substance that the aphids leave behind, known as honeydew.
If you catch a small group of them in time you can clean the area and remove infected leaves. Rinse the foliage once a week for a month or so to knock the bugs away, to get rid of minor infestations.
Insecticidal soap can help with larger infestations.
Mealybugs can also infect this plant. These pests are white and are found on the stems. It’s important to catch these bugs early as the longer they infect your plant, the harder it is to get rid of them.
The best way to avoid problems is to be vigilant and make sure you’re checking your plants regularly.
Browning or Yellowing Leaves
Now that you know about the common pests that infect cast iron plants, there are other issues to watch out for when growing this plant in your home. The main two issues that can happen are browning tips and the whole leaves turning brown in color.
The reason for both these issues is often because you’ve watered too much, or there has been too much sunlight exposure.
Feel the soil? Is it soggy? Stop watering until the top inch dries out. Then, be extra careful going forward not to overwater. If the soil doesn’t feel too wet, try moving your plant to a shadier area.