Cast Iron Plant
Named for a reason. Deep green, strappy leaves that shrug off low light, dry air and neglect. Safe for pets, which is rare in the tough-plant club.
The Victorian parlour plant. It survived gas lamps and coal smoke in nineteenth-century sitting rooms, so it will survive your hallway. Each leaf rises on its own stem straight from the soil, and a mature clump makes a dense, glossy mound.
It is one of very few tough, low-light plants that is also safe for cats and dogs, which is why it comes up so often in our recommendations.
Light
Low to medium indirect light. A north window or a dim corner suits it. It is one of the few plants that genuinely prefers shade indoors; bright light bleaches the leaves and direct sun burns them. Variegated forms want a little more light to hold their stripes.
Water
Let the top half of the pot dry out before watering, about every ten days in summer and every two to three weeks in winter. It tolerates drying out completely far better than sitting wet. Brown tips are usually tap water rather than thirst.
Soil and potting
A standard potting mix with perlite for drainage. It grows slowly and likes being snug, so repot only every three years or so, in spring, when the rhizomes fill the pot.
Feeding
A half-strength feed every eight weeks in spring and summer. It needs very little; overfeeding burns the leaf tips.
Propagation
Division in spring. Unpot, separate the rhizome into sections with two or three leaves each, and pot them up. New divisions sulk for a few months and then settle.
In a hot, dry home
A reliable plant for dry, air-conditioned rooms. It does not care about humidity and it takes cold drafts and hot rooms alike. Keep it out of direct sun through glass and use filtered water if brown tips appear.
Problems and fixes
Brown leaf tips
Likely cause: Fluoride or salts in tap water
Fix: Switch to filtered or rain water and flush the pot every few months.
Pale, washed-out leaves
Likely cause: Too much light
Fix: Move to a shadier spot.
Yellowing leaves, soil wet
Likely cause: Overwatering
Fix: Let it dry out further between waterings.
Cast Iron Plant questions
Is the cast iron plant safe for cats and dogs?
Yes. It is non-toxic, which makes it the best truly low-light plant for a house with pets.
How much light does a cast iron plant need?
Very little. A north window or a shaded corner is ideal. It is one of the few houseplants that dislikes bright light.
Why is my cast iron plant not growing?
It is slow by nature, a few new leaves a year. That is normal. It grows fastest in medium light with regular water in summer.
Plants with a similar rhythm
ZZ Plant
- Light
- Low to bright indirect
- Water
- Every 3 weeks
- Pets
- Toxic
