A yellowing leaf on your Monstera deliciosa (the Swiss cheese plant) is the plant telling you something is off—but the message isn't always the same. The most common cause by far is overwatering and the root rot that follows, yet the exact same yellow leaf can come from underwatering, harsh sun, a nutrient shortage, low humidity, or simply old age.
The good news: each cause leaves its own fingerprints. Below is how to read those clues, narrow down the real culprit, and fix it without guesswork.
First, read the pattern before you act
Before changing anything, look closely. The position and pattern of the yellowing tells you most of what you need to know.
- Which leaves? Lower and inner leaves yellowing usually points to watering, aging, or nutrients. Upper or sun-facing leaves point to light.
- How fast? Several leaves yellowing suddenly suggests a root problem (overwatering). One old leaf slowly fading is often natural.
- Soil and roots. Push a finger 3-5 cm into the mix. Soggy and sour-smelling means too wet; bone-dry and pulling away from the pot means too dry.
- Spots vs. uniform. Crispy brown patches differ from an even, all-over yellow.
If you're unsure, you can photograph the leaf and check the likely cause in seconds with a free app like Agrosphere, which scores plant health and suggests a fix from the image.
Overwatering and root rot (the most common cause)
This is the number-one reason Monstera leaves turn yellow. Roots sitting in waterlogged soil can't get oxygen, begin to suffocate, and rot sets in—so the leaves yellow even though the soil is wet.
How to tell
- Several leaves turn yellow at once, often soft and limp rather than crispy.
- Soil stays wet for many days; you may notice a musty or sour smell.
- Yellowing often starts at the base and lower leaves.
- Roots, when checked, look brown, mushy, or black instead of firm and white.
How to fix
- Stop watering immediately and let the top 5 cm dry out.
- Slide the plant out and inspect the roots. Trim any brown, mushy roots back to firm, light-coloured tissue with clean scissors.
- Repot into fresh, chunky, well-draining mix (potting soil with bark, perlite, or coco chips) in a pot with drainage holes.
- Going forward, water only when the top 3-5 cm is dry, and always empty the saucer so the pot never sits in water.
For active rot, some growers dust cut roots with cinnamon or a labelled fungicide. If you use any fungicide, follow the product label and local regulations exactly.
Underwatering
Too little water causes yellowing too, but it looks and feels different from overwatering.
How to tell
- Soil is dry, hard, and may pull away from the pot's edges.
- Leaves yellow but also feel thin, droopy, or develop dry, crispy brown edges.
- The whole plant may look slightly wilted and the lightest pot is suspiciously light when lifted.
How to fix
- Water thoroughly until it runs from the drainage holes, then let excess drain away.
- If the soil has gone hydrophobic (water runs straight through), bottom-water: stand the pot in a tray of water for 20-30 minutes so the mix rehydrates evenly.
- Settle into a rhythm—usually watering when the top 3-5 cm dries, which often means roughly once a week indoors but varies with heat and light.
Too much direct sun
Monsteras are understory plants that prefer bright, indirect light. Long hours of direct sun—especially through a hot south- or west-facing window—scorch the leaves.
How to tell
- Yellowing and bleached, pale, or brown crispy patches appear on the leaves most exposed to the sun.
- Damage is on the side facing the window, not the shaded interior leaves.
- Sunburned tissue often looks dry and papery rather than soft.
How to fix
- Move the plant a metre or two back from the window, or filter the light with a sheer curtain.
- An east-facing spot with gentle morning sun, or bright indirect light, is ideal.
- Sunburned patches won't turn green again—trim badly damaged leaves once new healthy growth appears.
Nutrient deficiency
If watering and light are fine, the soil may simply be exhausted—common in plants that haven't been fed or repotted in a year or more. Nitrogen, magnesium, and iron shortages all show as yellowing, but in distinct patterns.
How to tell
- Nitrogen: uniform pale-yellow on the oldest lower leaves first, with slow overall growth.
- Magnesium: yellowing between the veins while the veins stay green, again on older leaves.
- Iron: similar interveinal yellowing but on the newest top leaves.
How to fix
- During spring and summer, feed with a balanced liquid houseplant fertiliser (for example an NPK around 20-20-20) at half the label strength, roughly every 2-4 weeks.
- For confirmed magnesium shortage, a dilute Epsom salt solution (about 1 teaspoon per litre) once or twice can help.
- If the plant is severely pot-bound, refreshing the soil through repotting often solves the problem on its own.
Always follow fertiliser label rates—over-feeding burns roots and causes more yellowing, not less.
Natural aging and low humidity
Two gentler causes round out the list, and they're easy to mistake for a crisis.
Natural aging
As a Monstera grows, it sheds its oldest leaves to fund new ones. If a single lowest leaf slowly yellows while the rest of the plant looks healthy and is pushing out new growth, this is normal. Just snip it off at the base—nothing is wrong.
Low humidity
Monsteras are happiest at 50-60% humidity. Very dry indoor air—near heaters, vents, or in winter—tends to cause brown crispy edges and tips first, with some yellowing alongside. To raise humidity, group plants together, use a pebble-and-water tray under (not in) the pot, or run a small humidifier nearby. Misting helps only briefly.
A quick diagnosis checklist
Run through these and you'll usually land on the cause:
- Soil soggy + several soft yellow leaves? Overwatering / root rot—check the roots.
- Soil bone-dry + droopy, crispy yellow? Underwatering—soak thoroughly.
- Yellow/bleached patches on the sunny side? Too much direct sun—move back or diffuse.
- Even pale leaves or yellow-between-veins, slow growth? Nutrient deficiency—feed at half strength.
- One old lower leaf, rest thriving? Natural aging—just trim it.
- Crispy brown edges and tips in dry air? Low humidity—raise it.
When the symptoms overlap and you'd like a second opinion, scanning the leaf with Agrosphere can confirm the likely cause and treatment before you commit to a fix.
Not sure what’s wrong with your plant?
Point your camera at the leaf and Agrosphere names the problem and the exact fix — free, offline, in your language.
Open AgrosphereFrequently asked questions
Should I cut off yellow Monstera leaves?
Yes—once a leaf has turned fully yellow it won't turn green again, so removing it lets the plant redirect energy to healthy growth. Snip it at the base with clean scissors. The key is to also fix the underlying cause so new leaves don't yellow too.
Will a yellow Monstera leaf turn green again?
No. Yellowing means the leaf has lost its chlorophyll, and that damage is permanent. Focus on correcting the cause so future growth stays green rather than trying to revive the yellow leaf.
How can I tell overwatering from underwatering?
Check the soil and the leaf texture. Overwatered Monsteras have wet, sometimes smelly soil with soft, limp yellow leaves; underwatered ones have dry, hard soil with droopy leaves and crispy brown edges.
How often should I water a Monstera to prevent yellowing?
Water only when the top 3-5 cm of soil is dry, then water thoroughly and let it drain fully. This is often about once a week indoors, but it varies with light, heat, and season—always check the soil rather than following a fixed schedule.
Is it normal for a Monstera to have one yellow leaf?
Often, yes. If a single oldest, lowest leaf slowly yellows while the rest of the plant is healthy and growing, it's usually natural aging. Worry only when several leaves yellow at once or new leaves are affected.
Can low humidity cause Monstera leaves to yellow?
It can contribute, though dry air usually shows as crispy brown leaf edges and tips first. Monsteras prefer 50-60% humidity; raising it with a pebble tray, grouped plants, or a humidifier helps.