Philodendrons (Philodendron spp.) come in a large variety of shapes, sizes, and colors.
There are Philodendron species with vining or tree-like growth habits, sport small or massive leaves, and range in colors from green to pink, white to red, and just about everything in between.
There are even some types with reddish-brown foliage. But if the leaves start to turn brown when they aren’t supposed to be, it means something is wrong with the philodendron plant.
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In our guide to growing philodendrons, we provide an overview of how to care for species in this diverse genus. Our roundup of 41 exceptional varieties provides an insight into the top choices to grow at home.
So we know that brown leaves are a warning sign that something is amiss.
If you’ve noticed browning foliage the trick is to figure out exactly what is causing the problem and only then can you determine what to do to fix it.
That’s where this guide comes in. We’re going to go over 11 common causes of browning leaves in philodendrons. Here’s the lineup:
Why Philodendron Leaves Turn Brown
Narrowing down the problem takes some detective work. Broadly, if the brown area on the foliage is sunken, water-soaked, or if it has a halo, it’s more likely to be caused by a pathogen.
Browning on philodendrons that primarily impacts older leaf growth and lacks these indicators is more likely to be caused by an environmental problem.
These rules don’t always apply, but they give you a good starting point for your investigation.
Here are the common problems that can cause browning in philodendrons:
1. Bacterial Blight
If the brown areas on the leaves of your philodendron have a foul smell, you should immediately suspect bacterial blight.
The bacteria Erwinia chrysanthemi and E. carotovora subsp. carotovora initially causes dark green, water-soaked spots, but these rapidly spread and merge to form large lesions.
Eventually the centers of the lesions might fall out leaving unsightly holes.
In time, the whole leaf will turn brown and mushy, with that foul smell I mentioned.
The bacteria can lay low in a dormant state during the winter, tricking you into thinking that you’ve gotten ahead of the problem, but it will rear its ugly head again when the temperatures warm up again.
Remove and destroy any symptomatic parts of your philodendron. If more than 50 percent of the plant is symptomatic, it’s best to toss it out, as treatment is unlikely to be effective.
A product that contains the beneficial bacteria Bacillus subtilis can help suppress the disease and can be used as a preventative.
Cease is an effective product that contains this beneficial bacteria.
CEASE Biofungicide
You can find it at Arbico Organics in gallon or two-and-a-half gallon containers. Follow the manufacturer’s directions carefully for application.
2. Bacterial Leaf Spot
Bacterial leaf spot is a disease caused by the bacteria Xanthomonas campestris pv. dieffenbachiae, which impacts many different species of houseplants, including philodendrons.
Symptoms start out as tiny translucent spots along the edges of the leaves.
Eventually, these turn reddish-brown and develop a yellow halo. It’s when the spots spread and merge that they turn light brown with irregular edges.
The bacteria that cause this problem need moisture to move and reproduce, so overhead watering, high humidity, and splashing water will encourage the spread.
Sadly, if your philodendron becomes infected with this disease, there’s nothing you can do about it. You’ll have to dispose of the specimen.
The bacteria can travel on infected plants, soil, tools, or even on your hands.
That’s why quarantining new houseplants when you first bring them home and washing your hands and tools before use is so important. Don’t slack on your houseplant hygiene!
3. Cold Injury
Most philodendron species hail from tropical regions, which means they aren’t adapted to cold temperatures.
Frost or freezing temperatures will likely kill the philodendron, but even temperatures that dip below 60°F can cause cold injury.
Even if you keep your house nice and toasty during the winter, walking your plant from the car to the house, low temperatures during shipping, or leaving a door open can potentially cause cold damage.
If you have single pane windows or doors that open straight to the exterior – rather than a garage or landing – the draft from one of these can be enough to cause injury.
Cold injury generally appears as black necrotic spots, brown spots, and wilted or wrinkled foliage. Once you realize that your philodendron has gotten too cold, move it to a warmer spot, if necessary.
Then, give it a week for all the symptoms to fully develop and then you can prune off all the damaged areas because they won’t recover.
They’ll drain the plant’s energy and can leave the specimen exposed to disease.
4. Leaf Spot
Leaf spot is less common on houseplants than it is on outdoor philodendrons, but the causal pathogens can be brought indoors on an infected plant.
Then, they can rapidly spread on water droplets in the air or on your hands.
If you inspect plants prior to bringing them indoors and wash your hands regularly when working with your houseplants, you should be able to avoid issues with leaf spot inside your home.
Pseudomonas leaf spot (Pseudomonas cichorii) initially causes small, water-soaked spots on the foliage that become large, dark brown spots with tan centers and yellow halos as the disease progresses.
Heavily infected philodendron leaves might turn water-soaked and brown, and will rot before falling off the plant.
This isn’t a species-specific pathogen. It can be a major problem in basil, celery, chrysanthemum, endive, lettuce, and pepper plants, to name a few.
It can live in the soil for months and when the temperatures are between 68 to 83°F with lots of moisture, the pathogens begin to reproduce.
Meanwhile, phytophthora leaf spot (Phytophthora parasitica syn. P. nicotianae) results in large, dark brown, water-soaked lesions that can kill the leaf and, eventually, the plant.
This disease, caused by oomycetes, doesn’t stick to philodendrons alone. It’s a serious problem on lupines, nightshades, onions, tobacco, and watermelons.
Dactylaria leaf spot (Dactylaria humicola) is specific to philodendrons and starts as small tan spots with depressed centers.
The spots themselves don’t typically grow as large as other leaf spot types. This pathogen is pretty rare and only tends to affect outdoor-grown specimens.
Unless you send a sample to a lab, it’s pretty hard to tell which pathogen is causing the leaf spots.
For that reason, it’s best to treat any of the above symptoms with a broad-spectrum fungicide. Copper is one option, though it’s not as effective as some of the products available.
A product like Procidic is effective against numerous pathogens, both fungal and bacterial in nature.
It harnesses the power of citric acid to kill pathogens on contact and also works systemically.
Procidic
You can find Procidic in 32-ounce ready-to-use spray bottles or 16-ounce or gallon concentrate containers at Arbico Organics.
Follow the manufacturer’s directions and continue using it until new growth emerges and no new symptoms develop for at least a few weeks.
5. Overfertilization
Overfertilization can be a cause of salt burn – discussed below – in that harmful minerals build up in the soil. But applying too much fertilizer can also burn the philodendron plant’s roots.
Browning leaf tips or margins and yellowing of the lower foliage is a pretty good sign that you should consider overfertilization as your main suspect for discolored leaves.
Overfertilizing can happen slowly over time or all at once from one major dose of food.
It can also happen if the potting mix doesn’t drain well and the fertilizer stays in contact with the roots for too long.
If you see symptoms and know you’ve possibly been a bit heavy handed with the plant food, just flush the soil to push those unwanted mineral salts out. We talk about flushing in more detail under salt burn.
A long, thorough soak can reduce the fertilizer salts in the soil by about 90 percent, so it’s highly effective.
And going forward, be sure to fertilize your philodendron more sparingly!
6. Overwatering
By many accounts, the number one killer of all kinds of houseplants is giving them too much water.
Most of the time, when I talk to someone who says they can’t keep their philodendrons alive, it’s because they’re overwatering.
I get it. I used to be guilty of it, too. So many plant care guides tell us that the way to keep houseplants happy is to water them once a week or so. But you should never water on a schedule.
You should water when your philodendron needs it, and the timing can vary from species to species and month to month.
A water-hungry plant might need twice weekly water in the summer and weekly in the winter.
Or a cactus might not need any water at all during the dormant season and just a bit here and there during the summer.
Overwatering and root rot go hand-in-hand. But while the root rot we talk about below is caused by a pathogen, rotting roots can also be caused by simply adding too much water to the soil, depriving the roots of oxygen and essentially drowning them.
If you overwater once, it’s no biggie, but repeated overwatering often leads to disaster.
The first sign that you’re being a bit too generous with the watering can will be yellowing and browning leaves that end up droopy and wilted.
They might drop from the philodendron, depending on the species, but not always.
The solution, of course, is to water less often. It’s always better to err on the side of providing too little water.
Usually, that’s enough to set your plant right, though if your plant is looking very sad and you want to be extra safe, remove it from the pot and toss out the soil. Trim off any dead roots and repot in fresh soil.
You might also want to treat for root rot as described below, as there’s always the risk that a pathogen is also involved.
Be sure that the drainage holes in the container aren’t blocked, and if your pot doesn’t have drainage holes, pick another one.
Be sure to empty the catchment pot or tray about a half hour after watering.
7. Root Rot
Symptoms of root rot are similar to those caused by overwatering, with the addition of pathogens in the Rhizoctonia and Pythium genera.
These fungal pathogens need lots of moisture to survive and reproduce, which is why they appear in soil that is overwatered.
When a plant has root rot, the leaves will first turn yellow, then brown, and the specimen will wilt. The foliage generally won’t fall from the plant. If the problem advances though, the entire plant will die.
If your plant is in a pot, remove it and wash away all of the soil from around the roots. Prune off any black, mushy, or otherwise compromised roots.
Wash the container thoroughly with hot, soapy water and then repot the plant in fresh soil.
Next, you need to treat the plant to kill any remaining pathogens. You should also treat any philodendron that is growing in the ground using the same process.
Luckily, biofungicides are effective against this disease.
There are options out there that contain beneficial bacteria Streptomyces lydicus and Bacillus subtilis, as well as beneficial fungus Trhichoderma asperellum.
Good old citric acid, thyme oil, and copper works, too.
I’ve saved several plants from a root rot death using copper fungicide and, my favorite product, Mycostop.
Mycostop is a biofungicide that harnesses the power of a bacterium called Streptomyces Strain K61, which is derived from sphagnum peat moss.
Mycostop Biofungicide
It makes quick work of root rot when you apply it to the soil and base of the philodendron.
Pick up five or 25 grams at Arbico Organics.
Learn more about how to deal with root rot in houseplants in our guide.
8. Salt Burn
We’re not talking about the kind of salt burn you get when you open your eyes while swimming in the ocean. This is the kind that occurs when mineral salts build up in the soil.
Soluble salts like sodium, chloride, boron, calcium, and magnesium can be present in municipal water and fertilizers. Some areas have higher mineral content in their municipal water than others.
As you irrigate your plants over and over with mineral-heavy water, the chemicals eventually build up in the soil.
The roots will take up these salts and it will cause the ends of your philodendron leaves to turn brown. Some species will drop their leaves, as well.
To prevent this from happening, you should flush the soil every three months or so. To do this, water your plant thoroughly until the liquid is running out of the drainage holes.
Wait five minutes or so and then water again until water is running steadily out of the holes again.
In addition to this, if you ever see a crusty layer of salt build up on the surface of the soil, scrape it off and replace the removed soil with fresh soil.
Every few years, replace the potting soil altogether. As potting soil ages, the organic matter breaks down and causes the soil to become compacted, depleted, and hydrophobic.
Keep an eye on containers made from absorbent material like terra cotta or unglazed clay. These materials can absorb mineral salts.
You can tell if the pot has absorbed salts because you will see white discoloration on the exterior.
While it might disappear if you wipe it with a wet cloth or when the container is wet, the white areas usually return when the pot dries out again.
If this happens, you can submerge the pot in water for 24 hours or so to dissolve the salts or just start with a fresh, new pot.
9. Southern Blight
Southern blight is a disease caused by the fungus Agroathelia rolfsii (formerly Sclerotium rolfsii).
It’s super common in vegetables like tomatoes and some ornamentals, but less common indoors.
If you use the same tools on your outdoor plants that you do on your houseplants, you can carry it from the garden to your indoor specimens.
Initially, it’s hard to tell whether your philodendron is suffering from southern blight or root rot. It starts with yellowing leaves that turn brown and wilt. As it advances, though, you start to see white and brown fungal masses. That’s what sets it apart.
The pathogen thrives in humidity and warm temperatures.
There isn’t a cure for southern blight except to toss out the plant and all the soil with it. Make sure you sanitize the container, too, using isopropyl alcohol or hot, soapy water.
There are products like Tenet WP available that contain beneficial fungi in the Trichoderma genera, and these can be effective at preventing the disease.
If you’ve dealt with southern blight before and you’re nervous it might come around, treat with Tenet WP according to the directions on the packaging.
Tenet WP
You can purchase 16 ounces of Tenet WP at Arbico Organics.
10. Sunburn
Sunburn happens when a plant is exposed to too much direct light, particularly in the afternoon when the sun is the hottest.
In the case of variegated cultivars, if the white areas of the foliage turn brown, it’s likely as a result of too much sun exposure.
Depending on the species, the suburned area may appear white to dark brown and usually has a papery texture rather than being water-soaked.
It’s usually only the leaves that were exposed to the brighter light, though it can show up in other areas if the plant is extensively damaged.
The solution, of course, is to move the plant into an area where it is protected from the harsh rays of the sun.
Cut off all the damaged foliage and if you want to move the philodendron into brighter light, that’s fine. Just do it slowly over a week or two.
11. Underwatering
Underwatering is usually far less of a problem than overwatering, but if you chronically underwater, the philodendron will develop dry, brown patches on the foliage.
If you find that the soil is constantly dry and your plants appear to be wilting before perking up when you give them a drink, you’re underwatering.
Still, I can tell you from my own experience that minor underwatering isn’t a big deal.
I wait until my heartleaf philodendron is just about wilting before I water it and it’s robust, happy, and growing more quickly than I can handle.
Err on the side of providing too little water if you aren’t sure how much or how often to irrigate your plants.
For most philodendrons, they like to have evenly moist soil. But that doesn’t mean the soil should feel wet or soggy.
It should feel like a sponge that you wrung out really thoroughly. You can even let the top inch or so of soil dry out between watering.
Prune off any leaves that are mostly brown, as they won’t recover and will just use energy.
Don’t Let Brown Leaves Get You Down
When a philodendron starts to develop brown leaves, you know something is wrong. It might be no big deal.
Maybe the plant was exposed to a little too much sun. Or it might be a serious issue that needs immediate attention, like root rot.
Regardless, we hope this guide sets you on the path to eliminating the brown and returning your plant to good health.
If you’re still having trouble identifying the issue, please let us know in the comments section below. We’ll do our best to help you out.
And for more philodendron growing know-how, put these guides on your reading list next:
