Philodendrons (of all varieties) are favored houseplants around the globe. They have easy growing habits, but training them to grow that way is another thing. The hard truth is that maintenance is only minimal with philodendrons when you get every aspect of its care routine spot on.
Anything off with its growing conditions can leave you with a sad, droopy, wilting plant with the philodendron leaves turning yellow or brown. Even just the brown leaf margins ruin what should be its beauty.
When faced with discolored leaves on philodendrons, you need to go through a checklist of possible causes, rule out what it can’t be, investigate what it could be and follow the guidance for what this plant needs to thrive.
Explore All of the Reasons for Philodendrons Leaves Turning Yellow or Brown
1 – The Circle of Life – Philodendrons Shed Old Leaves
Yellow and browning leaves on philodendrons are a part of its growing process. Mature leaves are at the base of the plant. Younger leaves are higher.
If you are seeing healthy new growth up top, but yellowing and browning leaves only at the base of the plant, that is normal.
Philodendrons shed old leaves then use the extra energy to push out new growth. You will only see this happen in spring and summer when the plant is actively growing.
The leaves yellow first, then brown, then drop. In the winter, the plant is dormant, so it will not need to shed old leaves.
2 – A Problem with Watering
There is a balance to strike with the soil moisture content. It cannot be soggy, but neither should it be dry. If you aren’t sure if you have watered your plant too much or not enough, this is how to tell:
- Leaves on philodendrons turn yellow and droop downward when the soil is too moist.
- Philodendron leaves turn yellow and brown at the leaf margins when they lack water.
If it only needs a drink, go ahead and water your plant and it will perk up. The fix for an over watered plant of any type is more tedious.
For that reason, it is safer to under water philodendrons than risk dampening the soil to the extent that it remains too soggy for too long.
Excessively over watered plants runs the risk of root rot, and a host of bacterial and fungal diseases that will damage the root system.
Philodendrons do not need to have an excessive amount of water added to the soil for it to struggle with moisture absorption. A slow draining soil or potting your philodendron in a pot without a drainage hole will result in soggy soil.
Check to make sure your container’s drainage hole is not blocked, and that water can drain freely from it. If it can’t, the soil may be compacted, in which case, either flush it, or repot in a fresh potting medium.
In the case of the drainage hole being blocked by the roots, then it is time to repot in a bigger container.
When repotting philodendrons that have outgrown their containers, go up by one size. Any larger can exasperate stress, prolonging the discoloration of philodendron leaves.
The ideal time to repot these plants is in the spring or summer to minimize the risk of transplant shock.
3 – Lacking Macro Nutrients, Philodendron Leaves Respond by Changing Color
Nitrogen is the main nutrient most plants require to keep their leaves green. Philodendrons need a little more in their plant diet than most plants. The two main macro nutrients they require are iron and magnesium.
To know which macro nutrient is lacking, test the soil.
The main two macro nutrients responsible for leaf discoloration on philodendrons are iron and magnesium. When these lack, philodendron leaves turn brown or yellow.
The Fix for an Iron Deficiency
Soil with a pH of 7 or higher is alkaline. Philodendrons need to have acidic soil close to 7. Above that, any iron that is available will be insoluble to the plant, indicating it is suffering from an iron deficiency. For iron to be soluble (usable), the soil must be acidic (pH below 7).
To fix an iron deficiency in plants, you can either add elemental sulfur or chelated iron into the soil. It will take time for the plant to heal once the iron becomes available.
Don’t expect yellow leaves to turn green. They’ll likely drop to make way for new green leaves and likely faster.
Note too that to fix the yellowing of leaves on philodendrons for the long term, the iron must be absorbed by the roots. Foliar sprays only apply the iron into the leaves. They do not contribute to the plant absorbing it through its root system.
The Fix for a Magnesium Deficiency
A magnesium deficiency is simpler to rectify than iron. All that requires is one or two teaspoons of magnesium sulfate, better known as “Epsom salts.”
Rather than apply Epsom salts to the soil then watering it in, dissolve it in a spray bottle and spray the yellow leaves. It has a faster reaction than waiting for the plant to absorb it from the soil.
4 – Low Humidity Causes Brown Leaf Edges Then Yellowing Leaves
Have a look at your plant and see what parts are discoloring. When humidity levels are not high enough for the plant, the leaf edges on philodendrons turn brown first, followed by yellowing of the entire leaf surface.
It looks like chlorosis, however, look closer at the leaf edges for brown tips before treating the plant with fertilizer. It may just need the humidity levels increased to fix the leaf discoloration.
How to Correct the Humidity Levels for Philodendron Plants
For those new to growing and caring for philodendron plants, know that these are tropical plants. Light and water are only part of the care package that philodendrons need.
A big factor that keeps them lush is the humidity. In other words, the water the leaves absorb from the moisture in the air around the plant.
A lack of air moisture will cause philodendron leaves to turn yellow or brown.
The correct humidity range for philodendrons is 50%+. Under that and the leaves will turn yellow or brown. The higher the humidity, the better for these tropical plants.
They can cope with humidity as high as 90%. If humidity ever does become too high for it, you’ll see the philodendron leaves curling.
5 – Unsuitable Temperature Range or Fluctuations Can Discolor the Leaves
With philodendrons being tropical plants, they need to have high temperatures. Not just for transpiration in the leaves, but also the soil.
The warmer the soil temperature is, the faster nutrient absorption becomes. A low soil temperature will slow nutrient uptake, resulting in yellowing or browning leaves. The temperature philodendrons are kept in is imperative to its health.
The preferred temperature to maintain is 60 to 80-degrees Fahrenheit. Outside of that range, the plant struggles to extract nutrients from the soil.
Remember too that the temperature drops at night time. If you keep your plant close to a window, or a drafty area, the temperature fluctuation (either too high during the day, or dropping below 60oF overnight) can stress the plant resulting in leaves on philodendrons yellowing.
Temperatures ought to be consistently stable to avoid stress.
6 – Excessive Fertilizing Burns the Leaves
It is not uncommon for philodendrons to be over fed fertilizers. Indoor gardeners often fertilize regularly because it is how to make a philodendron fuller. However, the caveat to frequent feeding is an excessive salt accumulation in the soil.
Too much salt can alter the soil’s nutrient availability, resulting in leaf scorch, aka, brown leaves.
The main danger of excessive fertilizing is creating a weak root system. Grow these too fast and there will be more foliage up top than the root system below the soil line can care for. The end result can be a fuller philodendron but with paler and smaller leaves that wilt.
To fix fertilizer burn on houseplants, flush the soil with enough water that let excess minerals wash out of the potting mix. Simpler is to remove it and replace the potting medium, effectively starting again with a new mix.
Also note that philodendrons go dormant in the winter. If you do regularly feed fertilizer, drop the feeding back to every two months in the winter.
7 – Bad Lighting Does More than Hinder Photosynthesis
Without light, photosynthesis is hindered. Overdo it with direct sunlight, the leaves turn brown (burn). Philodendrons do best when they are placed in a spot that receives bright indirect sunlight.
Another thing to keep in mind about the amount of light your plant receives is the effect the lighting has on the soil’s moisture content.
The more light philodendrons get, the faster the moisture absorption is in the soil, which then necessitates more frequent watering. They can tolerate partial and full shade, but the growth rate will be much slower and when that is the case, they require much less watering.
If you are growing philodendrons in the shade, be extra vigilant with the soil moisture. It is easy to add too much water resulting in the roots sitting in soggy soil. Inadequate lighting can contribute to over watering philodendrons.
An added to-do for the winter months – when the windows are closed and the dust levels increase indoors – is to wipe away dust from philodendron leaves because that will reduce the light the plant receives.
8 – Unsuitable Pot Shape for the Type of Philodendron
There are two types of philodendron plants. Vining varieties are the climbers suited for hanging baskets, or trained to grow vertically with a support stake to climb up. Examples of these varieties are the Heartleaf Philodendron, and the Philodendron Brandtianum.
The other type is the creeping variety. These are the ones with the largest/broadest leaves with thick stems to support their weight. Examples of these are the Philodendron Pastazanum and Philodendron Gloriosum.
Climbers favor a round plant pot. Creepers or crawlers ought to have rectangle and deep containers. The reason being that they get the “creeper” or “crawler” name because the rhizomes creep along the soil surface, the roots grow downward and the thick stems sprout upward.
Bury the roots of a creeping/crawling philodendron too deep, and the rhizomes won’t be able to crawl along the topsoil. Instead, they’ll struggle for air and continually perform worse. Leaves are big to start with and then get smaller, paler, and begin drooping.
If you are growing any of the many creeping/crawling varieties of philodendron plants, particularly, big leaf varieties, it may need a round pot swapped for a long, deep, rectangular planter.
Yellow leaves are likely to be because the plant is stressed from not being able to “crawl” as it naturally should.
9 – Pests Can (and Will) Dehydrate Philodendrons
On the topic of creepers and crawlers, many creepy crawlies are pests to philodendrons. Aphids, gnats, mealybugs, spider mites, and scale insects can suck these things dry.
They have leaf piercing mouth parts that penetrate the leaf surface, allowing the critters to drain the philodendron leaves of its juices/sap.
Where they pierce the leaf only shows like a yellow dot on the leaf. The problem with all of these pests is their rapid reproduction rate. When you get one, you usually get an army of them.
An infestation of any pest that steals your plant’s nutrients will result in leaf discoloration. It begins with a minuscule number of critters, then quickly spreads. Before you know it, you have an infestation to treat.
What type of treatment you use will depend on the type of insect infestation. Some are better than others. Like, for mealybugs, a cotton swab dipped in rubbing alcohol (isopropyl) will do the trick.
For gnats, you’d be better preparing a Neem oil solution, preferably a blend of Neem oil extract and castile soap. It acts as a contact poison to insects. This kills the insects and the larvae they infest your potting mix with.
If you suspect a pest infestation, quarantine the plant from any others you have to prevent further spread, and have a look over this list of ways to get rid of bugs on indoor plants and pick the one that makes the most sense for eradicating the type of pest you need to get rid of.
Most require repeat applications, but all of them will put your philodendron on the fast track to producing new lush green leaves that stay that way.