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What Causes Brown Spots on Snake Plant? (And How to Fix It)

Fungal diseases, pests, and improper watering are the most common causes of brown spots on snake plants. Excessive fertilizer application, frost, and extreme sunlight exposure can worsen this problem. Apply a copper-based fungicide and use a natural or chemical pesticide to eliminate the bugs.

If there was a prize for the toughest houseplant, the snake plant would be a strong contender. Snake plants can withstand drought, insects, and low light.

Even the most disease-resistant plant, however, can become infected with diseases that wreak havoc on its growth and appearance. One of the most common diseases on snake plant leaves is brown spots.

This article will cover the causes of brown spots, effective yet simple remedies, and how to keep your snake plant disease-free.

Causes of Brown Spots on Snake Plant

Brown spots on your snake plant can occur for several reasons. Inappropriate watering or fungal issues all boil down to poor treatment.

Fungal Diseases

Sticky brown fluid will ooze out of the squishy spots.
Sticky brown fluid will ooze out of the squishy spots

Snake plants are susceptible to fungal diseases like southern blight and red leaf spots, which cause reddish-brown lesions on their leaves. Squishy brown spots will form, secreting a sticky brown fluid as they soften.

Rust and bacterial leaf spots are two other infections that cause brown wet spots on the leaves of plants.

Let’s take a closer look at the three fungal diseases that may be causing your snake plant leaves to turn brown.

Red leaf spot

There’s no doubt that red leaf spot is to blame if you notice red or brownish-red spots on your snake plant.

Conditions that favor the growth and spread of this disease include high humidity and warm temperatures.

Southern Blight

Snake plant showing brown spots symptoms due to fungal infection.

Sclerotium rolfsii fungus is the cause of this soil-borne disease. Wet and hot conditions are ideal for the growth of this fungus. Thus, drainage problems or excessive watering can encourage this disease.

The snake plant will begin to turn yellow and brown as it attacks the root system. If you do nothing, you could lose your snake plant.

Rust

Rust on Snake Plant
Spots Due to Rust on Snake Plant

Even if snake plants aren’t prone to this, it can cause rust-like brown spots on the leaves.

Fungi of the Heterobasidiomycetes subclass infect living plant tissues, particularly leaves, and cause rust. Rust fungi do not feed on dead organic matter, so they move from one plant to the next after sucking the sap.

Snake plant rust often appears first on the leaves, and if it is not treated in a timely manner, the entire plant can be killed by the disease.

How to Prevent Fungal Problems

Ensure your snake plants have adequate airflow around them and inspect any new ones you bring home for fungal infections.

Treatments for fungal infections include the following:

Treating Southern Blight

It’s possible to prevent the rotting of your leaves by applying fungicides and using heat treatment (solarization) to combat southern blight.

A fungus/bacteria that Sansevieria is susceptible to spreads when the leaves are wet. Try not to get any water on the leaves when watering the soil.

Red Leaf Spot Treatment

You can cut the infected leaves to prevent the reddish-brown spots from spreading to other areas as a treatment.

My snake plant was infected with a red leaf spot, a fungal infection, and I cut off all of the spots to stop it from spreading. I haven’t had any problems since then.

Fungicides with copper and sulfur properties can be sprayed on as a preventative measure

For the treatment of fungal diseases. Here are the fungicides I recommend:

Name of The FungicideAmountAmount of Water
Bonide 811 Copper 4E Fungicide1-4 tablespoons (.05-2.0 fl oz)1 gallon of water
Garden Safe Brand Fungicide32 tablespoons (1 fl oz) 1 gallon of water
Southern Ag – Liquid Copper Fungicide3-4 tablespoons1 gallon of water

Rust Treatment

As with red leaf spots, rusts can be treated with the removal of the infected part.

As a precaution, you should also remove any remaining infected leaves and limit water contact to prevent the further spread of rust.

Bacterial Leaf Spot Treatment

This disease is caused by Pseudomonas spp. or Xanthomonas spp. and appears in the form of water-soaked spots that eventually become brown.

No recommended chemical treatment for this disease is available at this time.
Until now, the best solution has been mechanical treatment or removal of the infected part.

Watering an infected pants should be done with caution, as the disease can spread through moist air and water splashes.

Pest Infestation

Snake plants are susceptible to infestations of mealybugs and spider mites. These pests suck sap from their leaves which leads to stress that results in the occurrence of brown spots.

How to Prevent Pest Infestation

The best way to avoid pests is to always check the leaves for any chance of infestation.

If the plant is already heavily infested, it is best to discard it in order to avoid the possibility of contamination of surrounding plants.

Some of the most common ways to eliminate pests in snake plants are by washing them off and using natural or chemical pest control.

Some organic methods of controlling pests are readily available in your own home like the following:

Soapy Water

This mixture of dish soap and water can dehydrate spider mites and aphids. To produce this solution, combine 5 tablespoons of dish soap with 4 cups of water and spray it onto the infected plant.

Neem Oil Spray

This natural insecticide and fungicide, are produced from the seeds of neem trees that are native to India. It can get rid of mites, scale, aphids, and other tiny insects.

This article goes into more detail about How to Get Rid of Bugs on Your Snake Plant (With Pictures) and shares some best tips to avoid pest infestation.

Alcohol Spray

This solution can effectively repel insects from houseplants. To create this solution, you can mix 1 or 2 cups of 70 percent isopropyl alcohol with a quarter of water.

Inconsistent Watering

Indoor potted snake showing brown spots symptom.

Inconsistent watering causes brown tips or brown spots on the snake plant leaves. It includes both overwatering and underwatering.

You may know that overwatering is one of the known issues when taking care of snake plants. It can cause rotting roots and plant decay.

You can treat root rot by transplanting your snake plant if you can identify it early. Here are the things you can do:

  • Repot the plant and use a mixture of perlite, grit, peat moss, or coarse sand as the new dry soil.
  • Simply cut the rotten ends of your leaves but try to save as many healthy leaves as you can.
  • Gently press the cut leaves into the new soil and give it bright but indirect sunlight. Keep the soil moist but not wet.

In addition, underwatering is an equally common problem for this type of plant due to its known water conservation properties, almost similar to cacti.

When underwatered, snake plants can get extremely dehydrated and show symptoms like the browning of leaves. If you have underwatered your snake plant, this article covers all you need to know.

How To Fix Inconsistent Watering Issues

One of the easiest ways to water your snake plant properly is to have a routine and monitoring to see if they need watering or have any other issues emerging.

When watering your snake plant, it is essential to only water the soil but not the leaves.

Spilling water on the leaves might make them vulnerable to fungal infection. And fungal infection is the main reason for brown spots on snake plants.

If you are not sure how much water your snake plant needs. Then check out this in-depth guide on how much to water your snake plant.

You May Also Enjoy: How Much Water Do Snake Plants Need? In-Depth Guide

Using City Water

Snake plants are sensitive to the type of water you are using when watering them.

Tap water or city is known to have chlorine which ensures that water is safe for human consumption. 

Snake plants show signs of stress due to sensitivity to this chemical. Chlorine accumulation in the soil will affect nutrient availability.

Potassium (K) deficiency can cause brown spots on the snake plant. So it is very important to use filtered or chlorine-free water for your snake plant.

How To Fix Unfiltered Water Issues

The most common fix to this is filtering the water with any regular water filtration system you have available.

You can also leave the water you intend to water your plant in sunlight for a day before using it.

You may know that sunlight is very effective in eliminating chlorine. Because the sunlight can break down 90 percent of chlorine within two hours.

You May Also Enjoy: How to Save Overwatered Snake Plant (sansevieria)

Excessive Sunlight

Snake plants can thrive even without too much exposure to sunlight. That’s another reason why it’s one of the best indoor plant options.

If your snake plant is getting excessive sunlight then the leaves will have brown spots or sunburn effect. Let’s say your snake plant is thriving in a room with indirect light. Now all of a sudden you decided to bring it to a place where it gets direct sunlight without acclimatization.

In this case, your snake plant absorbs excess energy that it can not handle. Eventually, it harms the leaves tissue and brown spots symptoms appear.

How To Fix Excessive Sunlight Issues

If your snake plant is not used to a certain degree of light exposure, make sure to gradually adjust the light and heat levels to make it easier for your plant to adapt.

So keep your snake plant away from direct sun exposure. It thrives well in indirect sunlight without any issues.

Finding out the optimal lighting condition for your plant is still the best way to ensure a healthy snake plant without brown spots.

Cold Damage

Snake plants are less tolerant of low weather conditions. Leaving them in a place where the temperature can go below 55°F (12°C) can be stressful.

If your snake has been exposed to chilly temperatures then the cell sap (liquids within the snake plant leaf cells) will freeze. As you know when water turns into ice it expands in volume.

So, the cell membrane ruptures and eventually dies. This situation is vulnerable to be infected with fungal and bacterial diseases. Consequently, your snake plant leaves will show brown spots on the damaged portion.

Extreme cold also damages the root system as the water may freeze to ice. That is why the roots are unable to take up enough nutrients and result in the appearance of brown spots on leaves.

How To Prevent Cold Damage Issues

Remember to avoid exposing your snake plants in temperatures below 55°F(12°C) to prevent the risk of cold damage.

Keep them between 65- 80°F (18- 27°C)  at daytime, and 55 -70°F(12-21°C) at night time.

Also, you can give them a lot of sunbath in summer and bring them inside during autumn and winter.

You May Also Enjoy: 10 Ways to Stop Snake Plant Leaves Curling

Excess Fertilizer

Due to their resilience, snake plants can survive even without fertilization. But excess fertilizer can harm your snake plant and you will see brown spots or fertilizer burn on leaves.

Due to excess fertilizer nitrogen and salt level may rise and it will cause the fertilizer burn effect.

How To Fix Excess Fertilizer Issues

You should fertilize your snake plant in spring and summer. A potted snake plant needs only a small amount of fertilizer during the growing season.

Make sure you do not overdo it. You can apply a little bit of worm compost to your snake plant pot soil. 

Another easy to use fertilizer for the snake plant is Shake ‘N Feed. You can use this fertilizer for your other house plants also.

Winter is a dormant period for snake plants, so fertilization during this period can be harmful.

Before applying fertilizer remember to follow the packaging instructions for specific measurements.

If you have put a little too much fertilizer, you can flush it by running loads of water through it.

Organic or compost fertilizers are slow-release fertilizers that provide more natural plant nutrients essential to growing a healthy houseplant.

It gradually breaks down into small amounts in a longer time span. Most of these fertilizers can last up to four months in just a single application.

Low Humidity

As snake plants require minimal watering, they also do not require high humidity levels.

Low humidity causes the leaves to lose excess water and is a very common cause of brown spots on snake plants.

How to Prevent Low Humidity Issues

To meet sufficient humidity requirements, keep relative humidity at about 40 percent.

You can also use gadgets, such as a digital hygrometer or a humidifier, to regularly check the humidity of the air around your plants.

You can also create your own humidifier by making a pebble tray. To create one, you would need a tray, some pebbles, and purified water.

Put the pebbles into the tray then fill it with water. Put just enough water to moisten the rocks.

You can now put the plant on top of your pebble tray. This will boost humidity by slowly evaporating the water around the plant.

Final Words

As you can see, most causes of brown spots on snake plants very closely correspond to proper care of these plants.

With proper care and nourishment, your beloved snake plant will be thriving in no time. After all, they’re the easiest house plants to take care of. Would you agree?

(Source: University of Florida, University of Maryland Extension)