Identifying 4 Causes of Brown Spots on Indoor Plants ( + Solutions)

It is never a nice feeling when you see your beloved houseplants developing brown spots on their leaves.

You start to feel that sinking feeling at the bottom of your stomach, when you realize there could be something wrong with the plants you have lovingly cared for each day, and you ask yourself, “Why do my plants have brown spots?”.

why do my plants have brown spots

At the Garden Bench Top, we have all crossed paths with brown spots and diseases on our plants. Unfortunately, it is a part of the experience of being a green thumb.

We want you to know, all is not lost. You have a great resource and community here to support you along your journey. In fact, it is part of the reason why we have made it our mission to put together the ultimate plant troubleshooting guide.

The goal in this part of the guide is to help you identify the possible issues that may be contributing to the brown spots that are appearing on your plants.

So, if you are ready, grab your detective hat and magnifying glass, because we are about to dive in.

How to Cure Your Plant from Brown Spots

Before we begin, we thought it would be a good idea to set your expectations regarding the journey you are about to commence.

Identifying and treating your plant for brown spots is a process.

We are not going to sugar coat the exercise for you. You are going to have to approach this problem with a process of elimination. It is going to take time and patience, testing and waiting for feedback from your plant.

First and foremost, we recommend reading this guide in its entirety and bookmarking it for future reference.

Then, we suggest systematically working your way down the list to see if your plant responds positively to the remedies provided for each potential cause of the brown spots.

If the issue persists, come back to this article and move to the next possible cause.

Continue until you have a thriving, happy plant once again.

Identify the Cause of the Brown Spots on your Plants.

Okay, so let’s get into detective mode and start diagnosing the symptoms of your plants’ brown spots.

Brown Spots Caused by Moisture Stress

A common cause of many plants difficulties is moisture stress. This either means a lack of water or too much water.

Both can cause brown spots to form on your plants leaves, and unfortunately, this is a never ending battle with keeping your plants looking vibrant and healthy. Especially for outdoor plants that are exposed to the constantly changing elements of the weather.

An Indoor plant is somewhat easier to maintain when it comes to keeping a constant water supply. Particularly if you are clever enough to install an irrigation system. If you are watering your plants manually, your plants may be susceptible to brown spots if you have an inconsistent watering routine.

What Does it Look Like?

When a plant doesn’t receive enough water, the leaves begin to dry out. You will notice the edges beginning to brown and look and feel crispy. The leaves will also begin to droop and look limp. This is your plant’s way of communicating to you to top up your water immediately!

On the other hand, the symptoms of too much water tend to appear as brown tipped leaves. You will notice the tips turning brown, and the longer you leave them, the browning leaf tips will extend to the rest of the leaf.

How to Solve the Issue

Moisture stress is usually an easy fix.

If your plant needs water, give your plant a big drink. Depending on how dry your soil is, you may see it hovering at the top until the soil is moist enough to begin absorbing the water again. Keep topping up the water until you can see the water coming out from the bottom of the pot.

If your plant is suffering from too much water, we recommend repotting your plant in some fresh soil. This will help to solve the immediate stress it is under. Then, going forward, employ the tried and tested finger soil test.

Grab a pinch of topsoil and rub it between your thumb and index fingers. If it feels dry, it is time to water your plant. If it is still moist, leave watering for another day. If it feels soggy, you may have overwatered again. It is time to adjust your watering regime.

Brown Spots Caused by Inappropriate Lighting Conditions

Too much direct sunlight can cause stress to your plant. Particularly indoor houseplants that require protection and prefer indirect light.

Not only does direct sunlight on a plant cause strain, the heat will dry out your soil quicker. This can then cause moisture stress (refer to previous cause), which then again compounds the pressure on your plant.

What Does it Look Like?

image credit: patchplants

To identify if too much sunlight is the cause of your browning leaves, check out the appearance of the brown blotches on your plant. If it looks like it has been burnt, and feels dry, then the sun may be a significant factor.

How to Solve the Issue

To solve your plants lighting condition problems, move the plant to a position that receives indirect sunlight. As the seasons change, you may need to play a bit of musical chairs with your plants and move them around to different positions, so they remain happy.

It will also be a bit of a waiting game to see if your plants respond to the new positions. Remember, patience is the key here.

Brown Spots Caused by Disease (including Fungus)

Disease can also be a cause of brown spots on your plants. However, the spots caused by disease and fungus definitely appear very different to those from moisture or light stress (refer to the ‘what does it look like?’ section below).

Unfortunately, brown spots caused by disease are generally only detected once the plant is already infected. So, the best approach is prevention. Immediately isolate any plants you suspect may be infected with the disease and fungus. This will help to prevent the spread to your other plants.

What Does it Look Like?

The spots that are caused by disease and fungus can be either brown or yellow (or both). They will tend to grow in size as the disease spreads across the plant. They also appear like an inverted embossed look on the leaf, like someone has stamped a spot onto the plant.

Brown spots of leaves from disease
image credit: getty images

You may also observe the spots beginning to spread to other leaves (and to other surrounding plants).

How to Solve the Issue

Immediately remove the leaves and sections of the plant that are affected by the disease/fungus. Also remember to sterilize any equipment that you use to make any cuttings, and discard any gloves that touch the affected areas.

Hopefully, you will have caught the disease early, so the plant has enough to survive.

Then apply some chemical agents (like fungicide) to kill off any areas that you may have missed.

Brown Spots Caused by Bacteria

Bacteria is another one of those pesky little things that you need to watch for in this wonderful hobby of ours.

In order for bacteria to thrive, it requires the right conditions. These are generally moist environments with high humidity levels, so overwatering can lead to a bacterial infection. You may also want to change your watering routine.

What Does it Look Like?

Brown spots that result from a bacterial infection look moist and can have that reverse embossed look (similar to brown spots caused by disease/fungus).

It is easy to distinguish between brown spots caused by moisture stress and bacteria, because the brown spots look a lot more saturated (compared to dry and crispy).

How to Solve the Issue

Like the fungus and disease method, isolate any plants that appear to have the bacterial infection. This is will prevent the spread of the problem.

Then remove any sections of the plant that are infected. Sterilize any equipment that is used in the process.

Since bacteria needs moist environments, cease watering the plant to allow the soil to dry. Then use the finger soil test method (described above) to understand when to water the plant again.

If you still notice more wet brown spots appearing, the infection may have advanced too far, and unfortunately you may need to discard your plant (they write as they try to hold back the tears).

Frequently Asked Questions (FAQ)

Often, when you think you have prepared and read everything you require in order to resolve your brown spot issue, an odd question pops into your head. This section is designed to help you with those odd questions.

Should I Cut Off Leaves with Brown Spots?


Unfortunately, once a leaf has developed brown spots (or yellow spots), the plant has already decided to discard the leaf. It is essentially sacrificing the leaf so that it can preserve energy and nutrients, so the remainder of the plant can survive.

How to Cut off Brown Tips from Indoor Plants

To remove brown spots or patches on indoor plants, take a sterilized sharp knife and make a cut as close to the stem or main plant as possible to remove the entire leaf.

As we mentioned in the previous question, you won’t be able to save the leaf by only cutting away the portion of the leaf that has the brown spots. It is best to remove the entire leaf, as this will also ensure you haven’t missed any disease/fungus or bacteria on the main plant.

What Deficiency Causes Brown Spots on Leaves

If you have made it this far through our guide, you will already be familiar with the deficiencies that can cause brown spots.

Under watering is a big deficiency that causes brown spots to develop on leaves.

How do You Fix Brown Leaves on Plants?

It is a process of elimination. Proactively diagnose the cause of the brown spots on your plant using our guide and implement the suggested solutions to return your plant to its vibrant self.