Potted palms are a classic, sophisticated addition to any indoor plant collection, but not one without its trials.
Browning palm fronds are a frequent and concerning problem for fans of indoor palms.
Palm leaf browning is mostly caused by exposure to direct sunlight and watering. Inadequate watering can result in browning foliage, root rot, and fungal infections in plants. Palms that have been damaged are more prone to pest infestations. Low humidity, insect infestation, and nutritional deficiency are all factors that might cause yellow leaves.
But never fear! It’s rarely a big issue, and I have put together an easy guide to diagnosing and treating your brown-leafed palm.
- Diagnosing Your Palm
- Natural Aging
- Over-watering and Root Rot
- Too Much Sunlight
- Nutrient Deficiency
- Fertilizer Burn
- How to Prevent and Treat Palm Diseases
- Frost Damage
- Low Humidity
- Insect Infestation
- Dealing with Pests
- Should I cut off Brown palm leaves?
Diagnosing Your Palm
Your potted palm can’t write you a letter of complaint, so when something goes wrong it shows in the condition of the leaves.
Different problems will impact the leaves in different ways, and you can often work out what the problem is by taking a good look at them.
Examine your leaves. Is the browning starting at the tip of the fronds and working back along with the leaf? Are the browning leaves in one spot, or across the plant?
Is it even, or is the browning spottier, like speckles or polka dots? Is the browning brittle and crunchy, or is it soft or oily to the touch?
Let’s take a look at what those different types of browning mean for your plant.
It’s first important to understand that the browning of your palm’s oldest leaves is natural.
If the browning starts at the tip of the oldest, lowest leaves and then gradually spreads until the whole leaf is brown and dry, it is simply the end of that leaf’s life cycle.
Your palm grows from the top, with new leaves sprouting from the crown as the old ones wither and die.
Depending on the species of palm, the older leaves are found at the base of the plant and will be larger and darker.
If your palm is producing plenty of healthy new growth, the brown fronds at the base are nothing to worry about. Prune them off and compost.
On the other hand, if your palm is browning from the tips inwards, evenly across your plant with little to no new growth, your plant is thirsty.
Palms do not hold much moisture in their leaves, so they benefit from consistently moist but not damp soil.
Take a look at your growing medium. Is it dry? Is it lose and crumbly, or worse yet – dried out into a single hard mass?
Lift your pot. Is it unusually light? These are all signs you need to water.
Thankfully an under-watered palm is very easy to treat. Just give it a big hearty serving of fresh clean water.
The best course of action is to water from below. This is the most effective way to ensure water penetrates deep into the root mass of your poor thirsty palm. To water from below:
- Place your palm in a basin or tub that is at least half as deep as your pot is tall.
- Fill your basin with filtered, distilled, or rainwater until it is halfway up the height of your pot.
- Watch the magic begin- the soil inside the pot will absorb the water, and the level in the basin will fall. Top it up to maintain a level halfway up the height of your pot.
- When the water level stabilizes, let your palm rest in the water for at least half an hour.
- Remove your palm. Allow any excess water to drain before returning it to its spot.
- Be sure to check cache pots, saucers, or trays in the hours after, and empty any excess water that may collect.
In the future, be sure to water your palm regularly. Depending on the species, you will need to water when the top inch or two of your growing medium is completely dry.
Depending on conditions and the time of year, it may be once a week or once a month, so it’s best to judge by the dampness of your growing medium.
Many busy gardeners set a reminder alarm in their phone calendars. I personally take an hour or so once a week to check the soil moisture of each of my indoor plants in turn.
While I simply touch the soil and feel the medium at a variety of depths, a moisture meter is a good tool for those interested in a precise idea of soil conditions.
Over-watering and Root Rot
It’s one of the great ironies of indoor gardening that an under-watered plant and an over-watered one often share the same symptoms.
If your brown leaves occur along with a potting medium that is boggy, smells unpleasant or your palm’s trunks and central stems are soft or squishy, it’s likely your poor palm is over-watered and it’s progressed to root rot.
The roots of your potted palm need pockets of oxygen in the medium. Without that, the roots begin to drown and die.
With its roots out of commission, water and nutrients can no longer reach the leaves and they dehydrate. It also leaves your plant vulnerable to a host of diseases.
The key to treating an overwatered palm is assessing the degree of over-watering. If the browning is mild and the soil smells fresh, just lay off the watering can and let your palm dry out.
Empty pots or saucers of standing water so the soil can drain. Some also suggest wrapping the bottom of the pot with an old towel to draw out extra water.
I recommend you check the roots of your potted palm for damage. If possible, loosen your pot and slide out your palm to inspect the roots, or scrape a little potting medium free at the top.
If your roots seem blackened, soft, or damaged you need to re-pot. Foul smells are a sign to watch for, as they indicate root-rot.
Things to consider:
- When re-potting for root damage, you do not need a larger pot. In fact, it may be prudent to go down a size. Your plant does not need empty space beyond the edges of its root mass.
- Your pot will need at least three well-spaced drainage holes, though the more the better.
- Potted plants are not fussy about their potting medium, providing it drains well. A good quality potting soil with plenty of organic matter such as peat moss, coir, or shredded bark is best. For an overwatered palm, consider adding sand or perlite to improve water flow in the future.
- If you find your roots are blackened and slimy, they are rotting and need extra care.
- Rinse them gently, and be sure to trim away any dead or dying parts with clean shears or scissors.
Too Much Sunlight
Most indoor palms are tropical varieties, adapted to the shadowy floor of the rainforests, and are vulnerable to sunburn.
But even vigorous desert palms will be damaged by too much direct sunlight. If your browning comes on suddenly and is only present on one side or one area of your plant, it’s time to check the light levels.
First, move your potted palm away from direct sunlight. Changing seasons change the angle and direction in which sunlight shines through windows, so be mindful when placing your plants.
Regrettably, for your sunburned frond, the damage is permanent. But unlike disease or deficiency, it doesn’t reflect on the leaf’s ability to provide food for your plant.
Provided more than half of the leaf is still green it will get the job done, so leave it on the plant until its natural lifespan is up.
Many care guides advise you to be stingy with your palm’s fertilizer, and with good reason.
Most indoor palms are secretly long to be trees, and an over-nourished palm grows to heights that are hard to house. But it’s easy to go too far in the other direction and starve your plant.
All indoor plants require regular fertilization. The limited medium in their pots can only keep them nourished for so long.
Palms in particular quickly run out of a few key minerals. Here’s a list of the most common nutrient deficiencies that contribute to yellow and eventually brown leaves.
|Nitrogen Deficiency||New leaves are bright in color, almost neon green to white. Overall growth slowed.||Spray leaves with nitrogen-rich foliar fertilizer, then apply slow-release nitrogen-rich fertilizer to the pot.|
|Potassium Deficiency||Translucent yellow to orange spots, brown dead leaf edges starting with older leaves.||Add slow-release potash with magnesium for support.|
|Magnesium Deficiency||Yellow banding along leaf edges starting at younger leaves. Tips turn brown and the leaves die.||Dilute solution of 1 tsp Epsom salts in a quarter gallon of water, sprayed over leaves monthly.|
|Manganese Deficiency||New growth is stunted and malformed, with brown patches. Leaf buds brown and die.||Dilute solution of manganese sulfate sprayed over leaves|
|Iron Deficiency||Leaf yellows while veins remain green. New growth is small with dead tips.||Check for root rot first, then apply chelated iron to the base of the plant.|
|Boron Deficiency||Stunted, yellow leaf tips. Leaves are brittle.||A strongly diluted solution of boric acid sprayed over leaves|
Foliar fertilizers are sprayed directly on the leaves. The minerals are absorbed directly and are quickly put to use.
But prevention is always better than cure. Most palms will only need a single application of slow-release balanced fertilizer in the early spring.
Even those like the areca palm that enjoy more fertilizer really only need a second dose in the summer.
A good option is to use palm fertilizer spikes. These spikes are slow-release and specifically formulated for the needs of indoor palms. They are fantastic to help avoid all the deficiencies I’ve just talked about.
Because palms need so little fertilization, it’s easy to go overboard and harm them. If you are overly generous your poor palm will find itself with more minerals than it can use.
These collect in the soil, eventually resulting in nitrogen buildup in the soil that damages delicate roots.
Fertilizer burn lives up to its name. Leaves will seem almost scorched, a bleached-out yellow that soon turns brown.
Another key giveaway is visible mineral salts on the surface of your potting medium.
The key to recovering your over-fertilized palm is to clear the medium of excess minerals. To do this:
- Remove any visible mineral salts from the surface of your potting medium.
- Remove your palm from cache pots, saucers or trays, and place over a drain or on open ground.
- Flush your plant with running water until the flow passes freely through the drainage holes of your pot. Allow the water to flush through for a few minutes.
- Remove the flow and allow your pot to rest for five minutes. This allows any remaining salt time to dissolve.
- Repeat step 3.
- Allow your pot to drain thoroughly before returning to cache pots, saucers or trays. Afterwards, check your palm periodically and tip out any water that may collect.
Here’s a guide to some of the more likely culprits responsible for browning fronds.
Also known as graphiola leaf spot, this fungal disease causes regular black wart-like growths to sprout all over the leaf surfaces.
These are “mushrooms”, the fruiting bodies of the fungus devouring the inside of the leaf.
This unpleasant fungal infection infects palms housed in drier, colder environments and interferes with your plant’s ability to make use of water.
Consequently, symptoms are identical to under-watering, with older leaves drying out from the tip of the frond down to the base.
If you’ve ruled out issues with your watering schedule, but your palm is still showing signs of thirst, it may well have fusarium wilt.
Ganoderma Butt Rot
Another fungal disease, Ganoderma first causes older fronds to wither and brown before drooping parallel to the stem or trunk of your palm.
New growth will be stunted and very pale in color. In severe cases, the entire crown may rot away, and it commonly infects roots, too.
Black lesions on your new buds and fronds are a sign you have bud rot. It’s caused by a variety of pathogens, including the harmful Phytophthora.
Older fronds often survive the onslaught for some time before they too succumb.
Leaf Spot Diseases
If your browning leaves are peppered with circular brown or yellow speckles that are sometimes oily, your potted palm is afflicted with one of the many pathogens that cause leaf spots.
It’s almost like a common cold for you and me – caused by many different nasties, but the outcome is the same – spotty, sickly leaves.
How to Prevent and Treat Palm Diseases
To prevent disease, it’s important to keep your plant in good condition. Keep it watered and fertilized appropriately, and in the right level of light for its species.
For all palms, avoid watering the crown of the plant. In an outdoor setting with plenty of sun and wind, any water that collects in the crown dries quickly.
But for indoor palms, it’s a recipe for disaster. That moisture trapped close to the youngest, most fragile part of the plant becomes the perfect playground for the pathogens that cause disease.
Never water your palm through its crown. Watering from below (as outlined above) is the best plan for palms.
For those who find that method too time-consuming, ensure your water is at the base of the plant rather than through the leaves.
If your best efforts fail and your potted palm falls ill, the treatment tends to be the same.
- Quarantine diseased plants immediately to prevent spread.
- Carefully prune away sickly fronds, with the exception of your crown. Diseased leaves must be disposed of in household garbage and never composted. For infections caught early, this may be enough to save your plant.
- For more severe infections, consider a copper-based fungicide.
- Some diseases, like phytophthora and fusarium wilt, are treatment resistant. If all treatment fails, you must bid a sad farewell to your sick plant and dispose of it entirely, pot and all.
One of the more peculiar problems your indoor plants may experience is edema, a condition caused by too much water retaining in the body of the plant.
Depending on the species, your palm may develop areas of quirkiness in otherwise firm stems and trunks, welts, and blisters that feel soft and mushy or ones that turn hard as the cells inside swell and rupture.
If the undersides of your browning palm fronds are covered in little irregular lumps and blisters, evenly across the plant, you may be dealing with edema.
Thankfully edema is easy to treat – simply allow your plant to dry out. Edema is caused by too much moisture, so easing up on the watering is the only treatment required.
While some palms are resistant to the cold, no species is frost-resistant. They are uniformly tropical and need warm temperatures to thrive.
If your leaves are frozen, they will first show brighter, richer green areas as the chlorophyll inside damaged cells become more visible. Later those areas will brown and die.
Prevention and Treatment
Once a frond is frost-damaged there is not much to do about it. Trim away the damaged leaf.
To prevent frost damage in the future, avoid placing your palm near windows in the cooler months, and be mindful of airflow.
A draft in an unheated hallway is a recipe for disaster. Make sure your palms are in a warm area of your growing environment.
Depending on the species, most palms prefer to be kept between 50- 80°F (10-26 °C) all year round.
Plants lose moisture through their leaves in a process called transpiration. It’s a little like how we lose moisture in our breath.
If you keep the palms in low humidity lose too much and their leaves dry up from the inside out.
Browning that works in from the entire edge of the older leaves is likely to be caused by inadequate humidity.
Aggressive air conditioning and home heating will draw moisture from the air and further dry your plant.
The amount of humidity required by palms varies quite a bit depending on the species.
Parlor and kentia palms will be happy at a comparatively low humidity of 40%, but others like cattails prefer 55% or greater.
It’s important to check what type of palm you have when considering your humidity.
That said, it’s tough to make a palm too humid, so aim for as much local humidity as your growing environment can handle.
A great tactic is to raise the humidity around your plants. Grouping them together will trap moisture lost through transpiration, allowing your palms to create their own area of moisture air.
A humidifier that is available on amazon works great for maintaining the humidity level.
A pebble tray is another option to raise humidity. To make one:
- Fill a shallow tray with large pebbles and stones.
- Add clean water until the stones are almost submerged.
- Place the tray near your plants, or keep the pot on the exposed surface of the stones.
- As the water evaporates, it adds humidity to the air. Be sure to keep it topped up to ensure best results.
Even the best-managed indoor plant collection will fall victim to pests from time to time. Here’s a rogue’s gallery of the more regular offenders.
These little pests are tiny, the size of pinheads. While they can be hard to spot, they leave gossamer webs between the fronds of your palms. They love to hide in nooks and crannies, sucking the sap from your poor palm.
Mealybugs are a group of insects that produce powdery, often fluffy shells to protect themselves.
If it looks like someone has dusted your palm with icing sugar or cotton fluff you are facing a mealybug infestation.
Tiny bugs with a taste for sap, these terrors can quickly suck the life from your plant.
They are prone to hiding away from sight under leaves or in the petioles of your palm.
Hard glossy bumps on your palm may not be part of the plant at all, but instead, the scales built by these pests. They hide from predators under the scales, draining sap from your plant.
Dealing with Pests
If caught early, they are very easy to treat. Wiping each little mealy bug or scale insect from your palm with a cotton tip soaked in spirits is a safe tactic, as is just spraying spider mites and aphids off under a gentle shower or hose.
But more severe infestations require more dramatic action. Quarantine your plant, and apply a topical insecticide.
Neem oil is a reliable favorite, sprayed over the canopy of your plant every five days until your infestation clears.
Should I cut off Brown palm leaves?
We keep indoor plants to admire the beauty of their sleek, fringed fronds, so the urge to remove brown leaves is strong.
Older leaves that have died off naturally can be pruned, as should fronds that are diseased or heavily damaged.
In general, however, it’s best to let your palm be. A little browning at the tips or around the edge of the frond will not stop your palm from using it to photosynthesize.
Growing new leaves is taxing, so it’s a good idea to avoid stressing your palm by over trimming it.
Browning is a natural part of the palm’s life. Keep it watered well, fertilized when needed, and away from hazards and pests and you will get years of pleasure from its sleep foliage.
Thankfully, even an imperfect palm frond brings its own authentic charm to any space that is lucky enough to house it.