Brown spots on new or old monstera leaves usually mean that the plant is getting too much water. This is one of the most common reasons for brown spots on monstera. Overwatered plants can start with black spots which can turn brown as the plant recovers.
When we get too excited as new gardeners it can be easy to give monstera to much water. Because they are a tropical plant I thought they would love lots off watered but I quickly discovered that they can quickly form brown or black spots because of this.
This caused my monstera leaves to form black spots which eventually turned brown as I slowed down the watering. The best way to fix this problem is to trim the leaves off.
I have left a leaf on my monstera to see if it would recover and the leaf recovered and is standing up straight. The brown patch has faded, but the leaf will never recover completely.
Removing the leaf is the only way to fully fix the problem. If you don’t mind the look of brown patches you can leave the leaf on there until it is replaced by new ones.
Top causes of brown spots on monstera leaves
While overwatering is the main cause of brown spots on monstera, there are lots of ways that this is caused. Here are the top problems that lead to monstera getting too much water and developing brown spots.
Pot trays or indoor pots
Monstera that are kept on pot trays or sit within an outer pot without drainage holes can suffer from root rot. When the monstera are watered it is important to allow any excess water to drip out of the pot rather than to sit in the bottom.
Any water that surrounds the roots can cause the monstera to absorb too much water and can turn the leaves black or brown.
To prevent this problem take the pot over to the sink or outside and water it so the extra water can drain out. Let it sit for 5 minutes to allow the extra water to come out, this can prevent the plant from absorbing too much water and turning the leaves brown.
Too much water given by you (or others)
Watering monstera can take a bit to get used to. They look like a tropical plant so it feels like they should be given lots of water. While monstera likes regular water it is easy to give them too much. Watering everyday can quickly lead to brown or black spots on their leaves so I discovered with mine.
Make sure you test the soil before you water the plant. Stick your finger in the top of the soil and see if it feels damp. Most monstera will only need water around once per week and to much water can cause brown spots.
Place your monstera outside in the rain once every few months to clean the leaves and water the soil. Make sure the plant can drain and bring it inside when the sun comes out.
Planting monstera in a pot that is too big
Monstera that are transplanted into a pot that is much larger than the pot it came in can lead to overwatering and brown spots. The increased amount of potting soil will keep the roots wet for longer and can cause root rot and leaf damage.
Monstera actually don’t’ mind being in a smaller pot and it can help to prevent them becoming too wet. When transplanting monstera choose a pot that is only 1-2 inches wider and deeper than the original pot.
How to get rid of brown spots on Monstera
The best way to get rid of brown spots on monstera leaves it to prune them off. If the leaf only has a small brown spot then it can be left on. While the brown spot itself won’t disappear completely the leaf can recover more generally and the rest can stay green.
One of the leaves on my monstera had turned black but after I reduced the watering it turned brown and the rest of the leaf has stayed green. This large leaf has been on my plant for months now and still looks good.
Causes of brown leaf edges on Monstera
Brown leaf edges on monstera is usually a sign that the plant is not getting enough water. Monstera plants that are too dry will show signed of this usually by drooping first. You will then notice yellow or brown leaf edges.
The simple solution to this problem is to water the plant well. Completely soak the soil using your tap or a watering can. This can be repeated again in 3 days and this should be enough to help your plant to recover. Add some seaweed solution to the water to help the roots to recover and rehydrate the soil.
Other causes of brown spots on monstera leaves
While fungus, insects or diseases of all kinds can affect monstera they are less common than overwatering. Check the leaves and stems for insects and see if you can notice any bugs sitting under the leaf, in the stem join or on the main stem.
Aphids are small and green while mealy bugs are brown and can form a white mold on the stem joins. Take the plant outside and wash off any visible bugs with a hose. Use neem oil to spray on the plant to treat any remaining pests.
Brown spots on monstera leaves | Summary
Brown spots on monstera leaves are most commonly caused by overwatering. Reduce your watering schedule and make sure the water can drain out of the pot. Avoid leaving the monstera roots sitting in water as they can quickly rot.
Other causes of brown leaf spots can be pest attack so check your plant carefully and squirt off any bugs you see with a hose.
Horticultural oils like neem oil will help with many pest problems but brown spots are most likely to be caused by water.
I am an accredited practicing dietitian, experienced gardener and a dedicated cook. I love writing and sharing my experience so you can learn from my successes and mistakes.