I run into so many people who love houseplants but just don’t have enough light for them. It’s also difficult to find plants that will truly thrive in the shade outdoors. Cast iron plant is one that can do both year-round.
Hardy to zone 7, cast iron plant is tough and versatile. It survives a wide temperature range. Its only weakness is too much sun, which will result in leaf scorch. This is rarely a problem indoors, but outside plants must grow in full shade.
Cast iron plants belong to the genus Aspidistra. There are about 100 different species in the genus but the most common is Aspidistra elatior. Most commonly encountered cast iron plants are of this species.
This species is a slow grower, but it lives a long time. For that reason cast iron plant is not common in nurseries, since
rapid reproduction usually means more profit. This is one of those plants often passed down from generation to generation.
While these plants grow slowly they are very easy to propagate. Plants produce many rhizomes and making divisions from them is easy.
Also, since cast iron plant is a slow grower it requires little water or fertilizer. Too much of either will not make it grow faster. In fact, too much fertilizer will make variegated types turn totally green.
This is a perfect plant for a college dorm room. They flourish from neglect and won’t suffer from being left on a cold dry window sill in between semesters. They tolerate it much better than that goldfish does.
Also, unlike many houseplants this one isn’t toxic to humans or animals, so it’s safe in any interior situation. Though not poisonous, it’s not edible either. Several sources state it has medicinal properties, but it isn’t a widely used medicinal plant.
Plants aren’t flashy. Leaves are dark green and have a rough textured appearance. Some types are variegated. Leaves look a little like peace lily foliage. However, plants rarely flower and when they do the flowers are often unnoticed.
If you’re lucky enough to see them, the flowers are really cool looking. They are usually purple or red and have very short stalks. Most flowers are eight pointed. Being borne close to the ground, flowers are pollinated by slugs and crawling insects.
Cast iron plants have few problems with insects or diseases. Spider mites and mealybugs are common pests but they usually don’t harm these tough guys as much as they do most plants.
If cast iron plants become infested you can take them outside and spray them with a water hose. This is a good way to whisk the dust off too. These plants can take the beating.
When planted outdoors cast iron plants are perfect under the dense shade of oak trees. Plants tolerate the light early in the season before the tree canopy develops. After that they require very little care and don’t need to be divided very often.
Plants thrive in well-drained soil but will tolerate soggy clay soil too. Extended periods of flooding can cause their downfall though.
Ted Manzer teaches agriculture at Northeastern High School.