Cast Iron: How to Grow Cast Iron Plant
Many people who live in a city or those who have limited space for a garden turn to indoor houseplants to make their home fresh, relaxing, and closer to nature.
However, choosing the right plant suitable for your space and environment is a dilemma, especially for first-time plant parents. Learning the characteristic of each plant and its proper maintenance might be too overwhelming. One mistake can make your plant wither.
Aspidistra elatior comes in many names such as parlor palm and bar room plant but it is most commonly known as the cast iron plant. The nickname suggests its survival capability in extreme conditions.
The cast iron plant is an herbaceous perennial plant, meaning it dies during the winter but reemerges in spring. This plant belongs to the family of lilies. It has long, pointed, leathery, green leaves and its purple or brown flower blooms near the soil. This type of plant has a lifespan of more than two years. It towers up to three feet tall and can be grown indoors and outdoors.
It is a popular plant in urban areas, homes, and offices for its known durability.
Facts About Cast Iron Plant
The cast iron plant is known for its longevity. A cultivated cast iron plant can live up to 25 years.
Many scientists were puzzled by the pollination process of the cast iron plant since its solitary flower grows directly from the rhizome or the plant's underground stem.
In 2017, two Japanese professors discovered that Fungus Gnat, a fruit-fly sized insect, is responsible for the pollination. The mushroom-like flowers of cast iron plants attract files with their scent and have them carry their pollens.
Aside from its ornamental use, the cast iron plant's rhizome is used in Chinese traditional medicine for the treatment of various illnesses.
The cast iron plant originated from the islands of Japan and Taiwan, although many mistakenly believe it came from China and the Himalayan region. It reached the peak of its popularity during the Victorian era in Europe, particularly in England, and America.
The cast iron plant is known for its indestructibility characteristic since it can withstand extreme conditions and is a low-maintenance houseplant.
As an indoor plant, it grows in mid-range lighting; direct sunlight can burn its leaves. It requires less water and is humid tolerant, but make sure to keep its soil moist when the air is dry.
When planted outdoors, its spot is usually under the trees where it can get most of the shade. It can also be an in-between filler plant in your garden or in potted patios. Direct sunlight and frequently wet soil may cause your outdoor cast iron plant to die.
The cast iron plant is an evergreen shrub or a plant that retains its leaves throughout the year. It resembles a corn plant with an individual flower that usually blooms unnoticed on the soil level.
The mature size of an indoor cast iron plant can reach up to two feet tall while the outdoor variety can grow up to three feet tall and three feet wide. Cast iron is a slow growing plant; it may take two to five years from planting to achieve its mature size.
Depending on the variety of the cast iron plant, the leaves that grow directly from the soil may have cream-colored stripes to solid green color. If not taken care well, the tips of the leaves may turn into yellow or brown. The size of its leaves may come in between 20 to 45 centimeters in length and 6 to 12 centimeters in width.
Mature cast iron plant blooms one at a time if the condition of the plant is right. Its small, bell-shaped, purple or brown flower is hidden under its foliage almost on the surface of the soil. The flower, however, is considered not attractive.
Varieties of Cast Iron Plant
Aspidistra elatior has variegated varieties but the most common cast iron plant has green leaves.
Also known as the Milky Way, Aspidistra Minor has short dark green leaves speckled with ivory or yellow markings. It has a dark green or black base foliage that contrasts the white spots on the leaves, thus earning its nickname.
Aspidistra Minor is the smaller variety of cast iron plant. It can only grow up to 10 to 15 inches tall.
The most common variety of cast iron plant is the Aspidistra Elatior. It has shiny, deep dark green leaves that grow up to 34 inches long. Aspidistra Elatior usually forms dense clumps.
It blooms a single purple or brown flower during spring.
Aspidistra Elatior is a slow-growing plant. It takes years to reach its mature size, but it can live for more than five years.
Aspidistra Elatior Okame
Aspidistra 'Okame' has a unique vertical white or cream stripe on its dark green upright leaves which reach up to 36 inches long.
This plant grows slower compared to non-variegated varieties of cast iron plant.
Aspidistra 'Okame' also requires more sunlight than the other varieties to keep its markings vibrant.
Aspidistra Elatior 'Goldfeather'
Aspidistra Elatior 'Goldfeather' is a rare variety of cast iron plant. This Goldfeather is more tolerant to winter compared to its relatives.
Its dark green leaves can grow up to 30 inches long and has light green and yellow streaks on the surface.
It is also the most fast-growing variety of the cast-iron plant.
Aspidistra Elatior 'Asahi'
Aspidistra elatior 'Asahi,' also known as Lime Striped Cast Iron Plant, has pale green leaves that can reach up to 20 inches long and 6 inches wide. This plant is famous for its frosted white leaf tips that are often described as snow peaks.
Aspidistra elatior 'Asahi' is perfect during the winter season since it tolerates cold weather well and complements it with its bright markings.
The word "Asahi" means "rising sun" and this plant is usually used for flower arrangement.
Aspidistra Elatior Variegata
Many people often confused themselves between Aspidistra Elatior Variegata and Aspidistra Elatior Okame since they almost have a similar appearance of having white vertical stripes.
While Aspidistra Elatior Okame has dark green leaves with upright white stripes, Aspidistra Elatior Variegata has creamy white foliage tinged with yellow or lime green marks.
Aspidistra Elatior Variegata is a much slower-growing variant of cast iron plant that needs more sunlight to keep its color vibrant and is less hardy to extreme conditions.
How to Grow Cast Iron Plant
Growing and maintaining of your cast iron houseplant will depend on its variant. Although the growing conditions of these variants are almost alike, it is still important to learn about the differences when it is planted indoors and outdoors.
The cast iron plant prefers medium-textured soil although it can still live with any soil type since this plant drains well. Using African Violet mix or any rich organic matter on the soil is also recommended.
Your plant will grow healthy if you use compost-based soil with pH-value ranging between 5.5 and 7.5.
Outdoor cast iron plant can grow in sandy or clay soil.
Moist but never too dry or too soggy soil is ideal for your cast iron plant. Overwatering can rot the roots, which can cause your plant to wither. Although it can tolerate skipped watering, it is better to keep your plant hydrated, especially during the dry and warmer season.
Ideally, you can water your plant once every two to three weeks if it is kept indoors.
You can personally check your plant if it already needs watering by inspecting the soil using your fingers. Allow two-thirds or at least 50% of the upper soil to dry out before giving its regular watering.
Rainwater is the best to use, but if unavailable, tap water is an option. Just make sure it’s stale as possible.
Remember to remove the leftover water from the saucer about half an hour after watering.
You can give your houseplant an occasional room-temperature water spray if the air is much drier.
Generally, the cast iron plant is capable of dealing with any lighting condition, except for direct sunlight. That is why this houseplant is an ideal ornament inside our homes. However, sitting in full shade may compromise its growth, but is barely noticeable since it is a slow-growing plant. Too much light may cause discoloration of the leaves.
When planted outdoors, it is better to place it under the trees where it can get the most shade. If potted in balcony or patios, make sure to put it in an area where it can avoid direct sunlight any time of the day.
Variegated cast iron plants or the colorful varieties need more sunlight than the plain ones to maintain its vibrant appearance. Still, direct sun should be avoided.
The cast iron is a perennial plant, meaning the exterior part including the foliage may wither during winter, but its roots underground remain alive and will regrow in spring.
This plant is known to be hardy on a wide range of temperatures, but it still has its limitations. The right temperature for your houseplant ranges from 10°C to 23°C.
The minimum temperature the cast iron plant can tolerate ranges between -5°C and -10°C. In this condition, the top part of the plant might appear to be dying, but the rhizome under the soil remains intact. The plant can survive winter, especially if planted outside. However, it will take time for it to regrow.
Your cast iron plant can take a maximum temperature of 38°C to 45°C if it is located in full shade.
Humidity is the last thing you need to worry about this houseplant. Your cast iron plant is not picky. It will do fine with any humidity level. That is why many people put this household plant in areas such as in the bathroom. Misting it with water is not necessary when the air is drier, but you can do so as a way to keep its appearance fresh and clean since its large leaves accumulate dust.
You can use liquid fertilizer on your cast iron plant at least twice a month during the summer and spring seasons. Using fertilizer during the fall and winter months is unnecessary.
Common liquid palm fertilizer is ideal for your houseplant. Remember to apply the fertilizer after watering the plant to keep the roots from burning. Avoid using fertilizer on the plant that has just been parted or repotted in less than a year.
Repotting and Propagation
As a slow-growing plant, the cast iron requires infrequent repotting. Young cast iron plant needs to be repotted every one to two years while the mature ones don't need any unless they outgrow their pot.
The best time for repotting is in spring. Remember to be gentle with its delicate roots when you do so.
The cast iron plant propagates through plant division. You can do the propagation during the repotting.
Plant division method means you need to carefully separate the rhizome or the root ball to two or more plants. Each root ball should have at least three stems or leaves to ensure its growth. It is preferred to use hands rather than knives when dividing the roots.
White-colored and string-like are sensitive roots, make sure not to damage those.
You can pot up the new plant into new potting soil, keeping it warm and moist until new shoots appear. Remember not to fertilize it yet until it has grown to a suitable size of the root.
Since your cast-iron plant is slow-growing, it rarely needs pruning, unlike other household plants that require frequent cuts to keep its neat look. Pruning is only necessary for this houseplant when removing dead, damaged or diseased leaves. Leaves that are damaged or discolored only on its tips do not need to be removed entirely. Cutting off the damaged part will do fine.
Diseases and Pests
Your cast iron plant is often described as indestructible by many people. Although they are known survivor of varieties of conditions, this plant is still vulnerable to bugs and diseases if not taken care of well.
Too much sunlight causes discoloration of the leaves of your cast iron plant. Remember that your plant prefers shade or filtered lights. Make sure to place them in areas where it is protected from direct sunlight.
Leaf blotch is the brown or black colored spots with bright yellow ring around it on the leaves of your cast iron plant. The blotches are caused by a fungus called Fusarium. If neglected, it may spread to the other leaves since the blotches release spores that infect the unaffected foliage.
Infected leaves should be pruned off the plant immediately. Make sure to disinfect your cutting tools after the pruning to remove the spores that have clung on your equipment.
You can also use broadband fungicidal on the plant to prevent the spread.
Root and Petiole Rots
Aside from overwatering, root rots are also caused by a soil-based fungus called Fusarium solani. This disease is difficult to treat so early prevention is the key.
Do not overwater your plant. As much as possible, keep your cast iron plant dry or moist to minimize the development of the fungus on the soil. Make sure your pot drains well. Remove the infected leaves immediately to prevent the spores from reaching the stem and soil.
If the roots are already infected, you can use fungicidal or biofungicide to limit the rotting.
Southern blight is the dark brown lesions or spottings that attack the stem caused by Sclerotia rolfsii. The wounds are usually found on the stem near the soil or beneath the soil level.
It causes the leaves to turn yellow and wither. Whitish mycelium of puffy masses forms on the affected parts and the soil around the plant.
The disease spreads if the soil is overly wet. You can treat the disease using a copper-based fungicide spray.
If you think the damage is already big, discard the plant immediately and make sure to apply new soil and disinfect the pot if you will use it in repotting a new plant.
Red spider mites form webs on the leaves and suck the sap out of your cast iron plant until it grows unhealthy and later on dies. It can infest indoor and outdoor houseplants. Due to its small size, red spider mites can only do a little damage. However, it can be a problem if numerous of it infested your plant. These mites reproduce quickly and usually invade plants during warmer and drier weather.
Shower your infested indoor cast iron plant with water. Make sure the entire pot is covered so the soil will not be washed out or drowned. Wipe the leaves of your plant using a moist cloth regularly. You can spray calcium-free water, rainwater or demineralized water.
If the invasion occurs in your garden, it is also recommended using its natural predators such as mesostigmata, lacewings and ladybugs.
Scale Insects and Mealybugs
Scale insects create a sticky honeydew on the leaves that attract ants and other fungal diseases. Scale insects damage and kills the foliage of your cast iron plant by sucking its sap. Most scale insects produce wax that protects them from their predators and repels insecticides.
Like scale insects, mealybugs feed on plant juices. It produces a wool-like web that covers the infected area of the leaf. Its body is also covered with wax.
You can spot the infestation of scale insects and mealybugs on your plant as they start to cover the surface of the leaves with webs and scales.
If you see an infestation, wipe the leaves of your cast iron plant with a cloth drained in ethanol for two days.
You can also coat the leaves with neem oil that contains azadirachtin, which kills scale insects and mealybugs.
Having a cast iron plant in your home is like having an independent and loyal life companion. Independent in the sense that it is low maintenance and almost live on its own. It is tolerant of extreme weather and environmental conditions, can survive days without water and rarely needs pruning. However, the cast iron plant is not fond of sunlight. It is happiest when placed under a shade.
Your cast iron plant is a slow-growing plant. It takes years to reach its mature size, and for that reason, it is more expensive than other plants in the market. The effects of fertilizers may be gone unnoticed because of its speed growth. This plant can grow up to three feet tall and three feet wide.
The cast iron plant can live for a decade if well taken care of. Variegated varieties of cast iron plant require more light than non-variegated to keep its colors vibrant. It produces a solitary flower hidden under its foliage if the plant is in good condition. It propagates through the plant division method.
Although the cast iron plant is indestructible, it is still vulnerable to diseases and pests. Make sure to check your plant up regularly.
Frequently Asked Questions
Is cast iron plant safe for pets?
The cast iron plant is non-toxic and is safe for humans and animals.
Can I place my cast iron plant outdoors in a warmer weather?
The cast iron plant can tolerate a wide range of temperature. It can take up a maximum temperature of 38°C to 45°C if placed under a full shade and watered regularly. Avoid putting it in areas where it can get direct sunlight any time of the day. Misting your plant with water during drier periods is fine. Aside from making your plant look fresh and clean, it can also prevent infestation, which is prevalent during warmer seasons.
Can cast iron plant tolerate cold?
Your cast iron plant can tolerate up to -5°C to -10°C. If your plant is outdoors during winter, the foliage may die due to frost and low temperature; however, the rhizome or the root underneath the soil remains alive. Your plant will regrow in spring, but it will take time to recover. Better to keep your potted cast iron plant indoors for hibernation before the first frost.