Cast Iron Plant is a well-known houseplant that is so tough and resilient growers often joke that the plant thrives on neglect. A slow-grower by nature, people often panic if the plant seems to not be growing and often ask how to help it when it’s not developing new leaves.
You can help a Cast Iron Plant grow new leaves through adequate and regular watering and providing it with bright but indirect sunlight. You may also repot it in an appropriately sized pot with a suitable potting medium and apply fertilizer accordingly.
In the rest of the article, I’ll share some care tips to encourage your Cast Iron Plant to grow new leaves.
1. Water the Cast Iron Plant Adequately
One of the main reasons a Cast Iron Plant stops producing new growth is because of poor watering practices. If the plant is getting too much water, give it a few additional days to dry out before watering again.
On the other hand, if the plant isn’t getting enough water, you may want to decrease the time between waterings. One of the telltale signs of an underwatered Cast Iron Plant is if it starts developing a yellowish color.
In general, once a week is adequate for watering. To be sure, check your Cast Iron Plant by hand. Push a finger a few inches into the soil to see if it is still damp or thoroughly dry.
You should only water once the soil has dried out completely.
In terms of moisture, Cast Iron Plant thrives in dry conditions because it is drought tolerant and doesn’t require a humid environment to be happy. In fact, the plant seems to be in better spirits when it is watered thoroughly and then allowed to dry out fully.
One of the best ways to water a plant like a Cast Iron Plant is to place it in a sink or a bathtub. Place the plant in an area where water can run freely through the pot and be allowed to drain out of the holes.
Prevent the plant from sitting in water. Place the pot up on a saucer or pebbled tray to let the excess water flow out of the holes. Throw away the water that accumulates on the plant saucer.
2. Inspect the Roots for Signs of Overwatering
While adequate watering is essential, watering too much or not allowing the soil to drain properly introduces new problems. Waterlogging is one of the biggest issues, so you want to make sure this isn’t happening. You also want to prevent it from happening in the future by taking preventative measures.
The best way to prevent waterlogging is to ensure the pot has plenty of drainage holes, especially at the bottom. Some pots may even have drainage holes on the sides, too, as this aids with further water drainage.
Waterlogging can subsequently lead to root rot, a fungal disease of the plant roots. Therefore, it’s imperative to ensure proper drainage when watering your Cast Iron Plant.
To check if waterlogging (and possibly root rot) is causing growth problems, remove the plant from the pot and examine the roots. If they look particularly mushy, root rot is likely the problem.
Other signs of overwatering include:
- Yellow leaves
- Droopy leaves
- Soft, mushy leaves
- Slow/no growth
Treating Root Rot
Below is a guide on how to treat root rot, allowing your plant to grow faster:
- Remove the affected parts of the roots. Anything that’s mushy and discolored needs to go. Use shears to cut away the infected roots.
- Replace the soil and disinfect the pot. The current soil may have fungal spores in it, so it’s best to replace it altogether. Cleaning the pot will also kill bacteria and fungi.
- Place the plant back in the pot. Once the pot is clean and the new soil is in place, you can place the Cast Iron Plant back.
- Clean the shears. If you used shears to cut away the roots, be sure to sanitize them to avoid spreading the fungus to other plants.
3. Improve the Light Conditions for the Cast Iron Plant
Another reason your Cast Iron Plant doesn’t grow new leaves is inadequate light.
Cast Iron Plant thrives in partial to full shade conditions outdoors. As a houseplant, they like just a bit of indirect sun. It doesn’t like full sun, even briefly, whether indoors or outdoors, and will likely show signs of stress after a short exposure.
A Cast Iron Plant is healthiest when placed in a location where it receives bright, indirect light from a nearby door or window.
There are many who swear that their Cast Iron Plant does just as well with an artificial light source. If you’re in a place with little or minimal natural light, play around with artificial light sources, making it as close to naturally indirect light as possible.
Move the plant closer to a light source, keeping it out of direct sunlight. If you don’t have much natural light, LED plant lights can supplement or replace natural light to keep your plants healthy.
Avoid Giving Your Cast Iron Plant Too Much Sun
Although it’s important that your Cast Iron Plant receives adequate sunlight, too much will stop it from producing new leaves. Plants that get direct sunlight may also display scorch marks on their broad leaves and could eventually stop growing.
Consider whether or not there’s a chance your Cast Iron Plant is receiving too much sunlight. For example, make sure it gets shade at some points during the day, especially if you live somewhere extremely sunny and hot.
Other signs to look for in a Cast Iron Plant that receives too much sun include:
- Dry, crispy leaves
- Stunted/no growth
- Droopy leaves
When a Cast Iron Plant receives too much sunlight, it’s more likely to become dehydrated, making the leaves turn dry and crispy. It will also be less likely to form new, healthy leaves.
At the first sign of brown spots or other signs of too much sun on your plant, you should immediately move your plant away from the light source.
4. Choose an Appropriately Sized Pot When Repotting
Ideal moisture conditions play a heavy role in the potting preferences of a Cast Iron Plant. Since the plant prefers low-humidity environments and roots that aren’t wet, consider a pot that drains freely, perhaps into a water dish or tray.
Self-watering pots are attractive but hold extra water at the base, creating more humidity than is ideal for this species. Solid-bottomed pots are also appealing to new plant owners since there isn’t the typical concern about water damage to the surface where the plant lives.
If your only alternatives are a self-watering pot or a solid-bottomed pot, you must be very cautious about how much you water the plant and create a bit more space at the bottom of the pot to help prevent root rot.
You can place a few inches of pea gravel at the bottom of your pot to help keep excess water out of the soil and root systems. Alternatively, you can use styrofoam packing peanuts to create that space without adding extra weight. Both will help to keep moisture away from the plant’s root structure.
There are also several issues associated with pot sizes that can prevent your Cast Iron Plant from growing new leaves.
The Pot Is Too Big for the Plant
Another plausible explanation for the plant not growing new leaves is that the pot is too large for the plant’s size. Frequently, plants come in a pot that is comfortably snug, if not slightly undersized.
A novice gardener will take this as a sign that the plant needs to be transplanted into a larger pot. While it sometimes may be the case, it isn’t always necessarily so. Check the bottom of the pot to see if you see densely packed roots through the drainage holes.
If you see roots, it may be time to transplant the Cast Iron Plant, but if not, it is often best to allow the plant to adjust to its new home. Most importantly, don’t assume the plant needs to be transplanted immediately.
If the plant does need to be repotted, it’s essential to choose a pot that is only one size bigger. Cast Iron Plants like to be somewhat snug in their pot without too much extra potting medium or room on the sides or the bottom.
If you repotted your plant in a significantly larger pot to give it room to grow but it isn’t thriving, consider repotting it to a smaller pot. A Cast Iron Plant doesn’t like to be rootbound, but they do succeed in a pot that is a comfortably snug fit.
The Plant Has Outgrown the Pot
Another possible reason your plant isn’t showing any new growth is that the plant has outgrown the pot. As is often the case, when the plant outgrows the pot, the plant has also depleted the nutrients in the soil, so repotting the plant is a practical next step either way.
Again, seeing dense roots through the bottom of the drainage holes is a good sign that the plant needs repotting. When this happens, it means your plant has become rootbound. Roots popping up through the top layer of dirt also indicate that the plant has exceeded the current pot’s size.
You want to choose a pot that is only a single size up from the current pot, and be sure you have a fresh, fast-draining potting medium on hand for the plant.
Alternatively, you can divide your Cast Iron Plant. It’s possible to disentangle the root systems and separate the plant into multiple divisions. Each division can be placed in a pot the same size as the original pot, along with a new, fresh batch of potting mix.
It may be more complicated than just repotting your plant, but it’s still a feasible task even for a new gardener. Check out my article for a complete rundown on how to repot or split a Cast Iron Plant: How to Divide a Cast Iron Plant (Complete Guide)
5. Use A Suitable Potting Medium
A Cast Iron Plant doesn’t particularly love wet roots, so quick-draining soil is ideal. Many potting soils on the market are formulated to retain as much moisture for as long as possible, making them unsuitable for your Cast Iron Plant.
Fortunately, there are a few alternatives. You can use a cactus mix partially or entirely in place of potting soil for your Cast Iron Plant. Another alternative is the African Violet mix, a fast-draining soil that helps prevent conditions that promote root rot.
One last alternative is to start with potting soil, supplementing it with additives that promote faster drainage. One common additive is landscaping or horticultural sand. Another additive is sphagnum peat moss. These can be mixed in a large bowl to encourage as much integration as possible before adding them to the pot.
If you suspect the soil is the reason your Cast Iron Plant isn’t growing, consider replacing it with new, well-draining soil. Use any of the recommendations above for the best results.
Check out my detailed guide on propagating Cast Iron Plants for more information on the subject: Cast Iron Plant Propagation in Water: The Complete Guide
6. Fertilize the Cast Iron Plant
If you’ve met all the steps discussed above and yet your plant is still unable to produce new leaves, it may be time to fertilize your Cast Iron Plant.
Plants need nutrients to grow and thrive, so without them, they can’t survive. Using fertilizer will add vital nutrients to the soil, and the plant will then receive those nutrients from the soil.
Cast Iron Plants only need to be fertilized every other month during the growing season. If you are fertilizing that frequently and it isn’t growing new leaves, you can increase feedings to every six weeks or so to see if that makes a difference.
Make sure you don’t over-fertilize your Cast Iron Plant because that can cause additional issues, like fertilizer burn. Stick to the recommendations on the fertilizer packaging or the above-mentioned guidelines.
You also want to make sure you choose an appropriate fertilizer. For example, you don’t want to choose a lawn fertilizer because it will contain too much nitrogen. Go with a fertilizer specifically designed for the plant. Better yet, get a soil test on the potting soil to determine which nutrients are lacking.
7. Give the Plant Some Time to Grow New Leaves
If you’ve tried all these things and the plant still isn’t growing, don’t give up. If your watering regimen, light, pot, soil, and fertilizer are all as they should be, this might leave you wondering if Cast Iron Plant is simply a slow-growing plant.
The Cast Iron Plant’s root system is a slow, steady spreader. As such, the plant aboveground is also slow to develop. More water, soil, light, or fertilizer will not change the pace at which a Cast Iron Plant grows, matures, or expands.
Instead of worrying about the growth specifically, be sure you’re doing the right things at the right time of year. For example, give the plant one last feeding as summer begins to fade into fall, knowing that the growing season is about to end.
As the plant enters the fall and winter dormancy, spread waterings out by just a few more days. Don’t stress the plant by repotting it during those winter months. Instead, wait until the first signs of spring.
Repotting or splitting a Cast Iron Plant is a great way to signal the start of the growing season to the plant. Be sure to follow that up with an initial round of fertilizer to be sure the growing season gets off to a good start.
After a time of little to no growth, people get frustrated with their Cast Iron Plant. They wonder if the plant is stressed or diseased. The question that I often hear is whether the plant will ever grow new leaves.
In all likelihood, the Cast Iron Plant will grow new leaves. Focus on giving the plant consistent care, and it has an excellent chance of developing fresh leaves. Take care not to provide the plant with too much water, light, or fertilizer.
You also want to avoid giving it too little of these things. You must aim for a good balance of the plant’s care requirements to encourage new and healthy growth.
Cast Iron Plants bring such a lovely color, texture, and beauty to any home. They are hardy and look beautiful next to other houseplants. They help clean your air and add more natural beauty to any room.
Be patient with the plant, acknowledging that it will grow on its natural cycle, not how quickly you’d like it to grow. Establish a solid watering and fertilizing routine, sticking to it as closely as possible, but staying flexible at changing seasons.
With time and regular care, your Cast Iron Plant will continue to grow and produce new vibrant and healthy leaves.