Why Is My Cast Iron Plant Turning Yellow?

The cast iron plant is a beautiful flowering plant that thrives in low light and high humidity. It can be grown as a houseplant or outdoors year-round. The plants usually have thick, succulent leaves with waxy surfaces.

If your cast iron plant starts to turn yellow then you may need to take action! This article will help diagnose the problem and provide solutions for getting it back to its original color.

Why is my cast iron plant turning yellow?

below I will list some of the most common reasons why your cast iron plant may be turning yellow.


The most common cause of a yellowing cast iron plant would be over-watering. Over-watered plants are more susceptible to mold and root rot, which can lead to the leaves developing brown spots or curling up at their tips.

If your soil seems moist even when you haven’t watered it in a couple of days, then you are probably overwatering it.

How to stop overwatering my iron cast plant?

The best way to stop overwatering your cast iron plant is by using a pot with drainage holes and making sure that the soil dries out before you water it again. This will not only keep the leaves from turning yellow but will also prevent root rot!

Another way to help stop yourself from overwatering your cast iron plant is by using a moisture meter along with a self-watering pot.

Fertilizer burn

Another common cause of a cast iron plant turning yellow is fertilizer burn. If your leaves start to turn brown around the edges and curl upward, then you may have too much or too strong of fertilizer in the soil.

This will usually happen after adding new fertilizers to an old pot with poor drainage because it can build up inside the soil.

How to treat fertilizer burn?

In order to treat a cast iron plant that is turning yellow due to fertilizer burn, you need to flush out as much excess fertilizer as possible by thoroughly watering it until water comes out of the bottom drainage holes.

If your pot doesn’t have any drainage holes then try placing some stones or pebbles at the bottom to allow for drainage. You can also try adding a layer of activated charcoal or peat moss on top of the soil and watering it in well.


If your cast iron plant has started to turn yellow/brown, then you should check if there are any brown spots around its leaf tips because this could be caused by too much sun exposure.

How to fix yellow leaves near tips?

You can help prevent your cast iron plant from turning yellow due to excess light by making sure that it stays in an area where the sunlight doesn’t directly hit its leaves for long periods of time.

Sunlight Deprivation

The reverse of the point above is also possible where a lack of sunlight can cause leaves to begin turning yellow and dropping off.

If there is a lack of sunlight, this will prevent your cast iron plant from getting enough chlorophyll, which can also cause its colors to become dull and pale.

How to fix lack of sunlight?

If your cast iron plant has started turning yellow or shedding leaves then you should move it into a sunny area so that its leaves can get the necessary amount of light they need in order for new ones to grow back healthy again!

Pests in the soil

Another reason why your cast iron plant might be turning yellow is if pests have infested the soil. These can include fungus gnats, root mealybugs, and scale insects. If you notice any of these bugs crawling around on or inside your potting mix then get rid of them as soon as possible because they can cause major damage to your plants.

How do I get rid of pests in the soil?

You should be able to kill any bugs or eggs that are currently infesting your cast iron plant by using organic pesticides like neem oil, horticultural oils, and insecticidal soaps.

If you don’t want to use any pesticides then you can try removing the infested soil and replacing it with a new potting mix.

Fluoride Toxicity

The cast iron plant is also susceptible to fluoride toxicity which can lead to yellow leaves. If you are growing your cast iron plant outside, then it may be absorbing fluoride from the soil or water source.

How to fix fluoride toxicity?

If you are growing your cast iron plant outside, then the best way to stop it from absorbing too much fluoride is by moving it into an area where there aren’t any nearby water supplies that contain excess amounts of this chemical.

You can also try using bottled spring water instead of tap or well water for your plant.

Mineral Deficiency

If your cast iron plant has yellow leaves but seems healthy otherwise (isn’t drooping over low light), then the problem may simply be a mineral deficiency. Mineral deficiencies such as nitrogen, phosphorus, or potassium deficiency.

How to fix mineral deficiency?

In order to fix a mineral deficiency, you should add fertilizer containing the appropriate nutrient. For example, if your cast iron plant is lacking potassium then try adding some cottonseed meal or other organic nitrogen/phosphorus source with added potassium sulfate.


In conclusion, if your cast iron plant has started turning yellow and dropping leaves, then you should consider checking to see if it’s getting enough sunlight or water.

You can also try moving the plant into a well-lit area but also that it doesn’t have too much exposure to direct sunlight for long periods of time.

If there are pests infesting the soil, then get rid of them by using organic pesticides.

If your cast iron plant has started turning yellow due to fluoride toxicity or mineral deficiency, then you can fix this problem by adding fertilizer with the appropriate chemical nutrients and minerals that it needs.

I hope that this blog post helped you learn why your cast iron plant might be turning yellow and you were able to turn this problem around so that your plant can grow healthily again!