What is Cast Iron Plant?
Cast iron plant (Aspidistra elatior) is native to Taiwan and southern Japan. It is related to asparagus. Like asparagus, it grows from an underground rhizome. Leaves grow directly from the roots rather than from vertical stems.
The plant got its name “cast iron plant” because it thrives with neglect. It lives happily in the dark corners of your house or yard, and rarely needs water. In fact, if you forget to water it and the rhizome dries out, you can revive the plant simply by watering and re-wetting the rhizome and new leaves will begin to grow.
Cast iron plants grow 24 inches tall and 24 inches wide with dark green leaves. Newer varieties have white and green leaves, yellow and green striped leaves, or white pointed leaves.
The plants’ flowers are difficult to see because they grow at the base of the leaves. They are cream in color with a maroon interior. Opening time is early summer. You won’t see seeds on your plants because the flowers are only pollinated by fungus gnats, which are native to Taiwan and southern Japan.
How to Grow Cast Iron Plants Outdoors
Cast iron plants are hardy in zones 6 – 11 so they can be grown outdoors year round in these zones. They are shade plants. If you plant them in the sun, the leaves will first burn (turn yellow and then brown) and then die. If you are growing them in containers, find a shady corner in your garden or on your patio. The north side of your home should provide enough shade to keep your plants happy.
Cast iron plants are not fussy about soil as long as it is well-drained. Overly wet soil or over-watering will cause root rot, which will kill your plant. Allow the soil to dry between watering. Use your finger to determine if the top inch is dry. If so, it’s time to water.
Cast iron plants are heavy feeders which means they need a lot of nutrients. Plan to fertilize your plant with an all-purpose liquid fertilizer every two weeks during the spring and summer. You can use time-release fertilizers instead of liquid fertilizers to save time. There is no need to fertilize in the fall and winter when the plant is at rest. Don’t worry if you don’t see much growth after fertilization. You don’t need more fertilizer. Cast iron plants grow very slowly.
How to Grow Cast Iron Plants Indoors
Cast iron plants can also be grown as houseplants whether you live north of the hardiness zone or not. They are shade plants so they are suitable for a dark corner where nothing else will grow or in a room with a north-facing window. They also don’t mind a dry environment, which is a problem with other houseplants that require you to either mist or create a humidity tray. Cast iron plants don’t care how dry your house is.
They take care of the soil. Make sure the pH of the soil you use is 5.5 to 6.5 and that it drains well. The pot you use should have a drainage hole. Overwatering or waterlogging due to lack of drainage will cause the roots to rot, which will kill your plant. Wait until the top of the soil is dry before watering.
Cast iron plants are heavy feeders. They need a lot of fertilizer. Unfortunately, a fact of life when growing plants in pots is that every time you water them, you are removing nutrients from the soil. Apply a time-release fertilizer or water with an all-purpose liquid fertilizer every two weeks. You can fertilize less frequently in the winter when the plants are resting.
Don’t expect to see a lot of growth on your plant. Cast iron plants grow very slowly. In fact, you may need to repot your plants into larger pots every 4 or 5 years. You’ll know it’s time to repot when you see roots growing over the edge of the pot. Repotting should be done in the spring when the plants begin to grow again after winter rest.
How to Divide Cast Iron Plants
A good time to repot your plant is a good time to divide it if you want more plants or want to share them with friends. Just separate the roots. Make sure that each piece of rhizome has roots and at least two leaves attached to it. Repot the new cuttings into fresh soil and water well. Keep your new sections moist and warm. When you see new growth, you will know that your section is growing new roots and can now be treated like any other houseplant.
