Why Does My Snake Plant Have Brown Spots?

Snake plants (Dracaena trifasciata) are famous for being impossible to kill. While that’s a bit of an exaggeration in my experience, it is true that these hardy succulents will tolerate near abuse without much complaint.

When problems do emerge, the first place you’re likely to notice symptoms is on your snake plant’s leaves. Brown spots are one of the most common issues reported by growers and can be hard to treat if you don’t know the underlying cause.

In this article, I’ll cover why your snake plant has brown spots and the best strategies I’ve learned to treat them.

Why Do Snake Plant Leaves Turn Brown?

If you notice brown leaves on your snake plant, the best-case scenario is that the foliage in question is either old or was physically damaged. Otherwise, brown spots are not normal.

Common environmental factors that cause this type of damage include harsh sun exposure, improper watering, and chemical buildup from tap water or fertilizer use. Brown spots can also be a symptom of fungal disease or pest activity.

Not only are brown spots a sign that something is wrong with your snake plant but they can also interfere with healthy photosynthesis going forward. Here’s why:

Chlorophyll is a crucial part of the photosynthesis process and is what gives plant leaves their green color. A lack of sufficient chlorophyll can make plant leaves appear yellow or faded. If the leaf tissue is severely damaged, it may turn brown or even black and will no longer perform photosynthesis.

What Causes Snake Plant Leaves To Get Brown Spots?

At first, you might have been worried about your snake plant’s brown leaves because, well, they’re ugly. But as I explained above, brown spots of any kind can also be a sign that your houseplant’s health is on a steep decline.

With any plant ailment, diagnosis is the first and often most important step. If you don’t know what caused the damage you have no way of effectively treating it or preventing it in the future.

In this next section, I’ve broken down the potential reasons your snake plant is developing brown spots and how you can narrow down the culprit. I’ve also included my own expert advice for treating common environmental problems.

Sun Damage

Despite growing wild in often very sunny environments, snake plants are well suited to low-light conditions. Growth naturally slows in dim lighting but we rarely see signs of illness or general decline.

In fact, the excess sun is responsible for many, many cases of brown spots on snake plants. In my experience, this problem is most common in plants grown outdoors (even if only for part of the year). But indoor plants can also be susceptible if placed in direct sunlight.

I often see sun damage on snake plants that have been relocated to a porch or patio for the summer months. The most likely explanation for this is that the grower didn’t slowly transition the plant to the brighter environment so it could ‘harden off’.

Snake plant with sun damage - Why Does My Snake Plant Have Brown Spots
Snake plant with sun damage

According to North Carolina State University, snake plants grow best when they receive 2 to 6 hours of bright sunlight. This exposure should ideally occur in the morning or late afternoon — not during midday when conditions are hottest.

Overwatering

The browning that starts as blisters or water-soaked spots on the leaves is often caused by overwatering. Drooping leaves are another common symptom.

The best treatment is to adjust your watering routine immediately. A good rule of thumb is to let the soil dry out completely between waterings. This usually averages out to watering every 2 to 4 weeks depending on the container size and time of year.

Ensure your snake plant has loose, well-draining soil and a container with adequate drainage holes. Do not place the container in a saucer that can collect water.

Snake plant with wet brown spots from overwatering
Snake plant with wet brown spots from overwatering

Root Rot

Overwatering can also contribute to more serious problems like root rot. I recommend examining the roots of your overwatered snake plant to check for signs of decay. Damaged root tissue can be cut off if the infection is caught early enough. Replant using fresh soil and a clean container.

Underwatering

Underwatering is less of a concern but can still cause problems over time. Visible symptoms of chronic underwatering include brown spots and dryness that develop along the leaf margins.

Going too long between waterings is the most likely issue snake plant growers will encounter. However, symptoms of underwatering can also occur if you don’t water deeply enough. It’s best to ‘soak’ the soil and allow excess water to drain from the container in a sink or tub.

Pest Infestation

There are a few common houseplant pests — i.e., spider mites and mealybugs — that seem to prefer all types of snake plants over other varieties. Brown spots on leaves are a tell-tale sign that these pests have been feeding.

Fortunately, infestations are easy to manage when caught early on. My go-to method is to physically remove pests by spraying the entire plant with water. Preventative treatments like Neem oil are highly effective and generally safe for use indoors. Remember to also check for signs of pest activity in the soil and replace it completely if necessary.

Fungal Disease

There are two fungal diseases known to regularly cause brown spots on snake plant leaves:

  • Red Leaf Spot — As the name implies, this disease causes reddish-brown spots to form on the leaves. The spots usually start small but grow larger and increase in number over a matter of days.
  • Southern Blight — This disease occurs when the fungus Sclerotium rolfsii attacks the plant’s root system. Damage to the roots eventually manifests as yellow or brown, wilting leaves. 
Snake plant with fungal growth
Snake plant with fungal growth

Infected leaves should be removed and destroyed as soon as possible to prevent the further spread of the disease. Fungicides can be extremely effective when used early and according to the manufacturer’s instructions. 

Be aware that fungal spores can spread to other plants in the area, so you may want to quarantine your snake plant until further notice. I also highly suggest addressing issues like poor air circulation or overwatering that can encourage fungal activity.

Poor Water Quality

Snake plants are relatively sensitive to chlorine and other chemicals commonly found in tap water. If your tap water has a particularly high chemical content, you might encounter symptoms such as leaves curling or brown spots on leaf tips or margins.

Distilled water and collected rainwater are usually considered best for houseplants of all kinds. You can also leave tap water to sit for at least 24 hours so that most of the chlorine content evaporates.

Fertilizer Burn

Brown spots on the tips or margins of snake plant leaves can also be due to fertilizer burn. This often happens when only the surface of the soil is watered and nitrate salts are left to accumulate in the soil. 

While good feeding practices will minimize the risk of fertilizer burn, I also recommend ‘flushing’ your snake plant’s soil when you water it. To do this, water thoroughly, letting excess water flow freely from the container’s drainage holes. Keep the container in a sink or tub until the draining stops.

FAQ Snake Plant Turning Brown

Should You Cut Brown Spots Off Snake Plant?

Yes, you can cut brown spots off of a snake plant to improve its appearance and prevent the spread of diseases. If only a small section of a leaf is damaged, consider leaving the healthy part intact. Avoid cutting away more than one-third of the plant at a time.

Citations

Website | + posts

Ben's horticultural interest grew when graduating from Hertfordshire University in 1997. Having contributed to numerous publications including Better Homes & Gardens, Garden Design Magazine, and The English Garden. He is also the author of Propagating Houseplants Made Easy.