Why is my monstera turning yellow?

Monstera deliciosa is the plant I get called about more than any other in Sarasota and Venice homes, and the call almost always sounds the same: it was beautiful, then a leaf went yellow, then another. Here is the good news up front. A yellowing monstera is usually a plant whose roots are unhappy, not a plant that is dying, and roots are the one thing you can actually check in five minutes.

The most likely cause: wet roots and not enough light to use the water

Monsteras are climbing aroids. In the wild they root into leaf litter and up tree trunks, in coarse, chunky, fast-draining material that is wet for a moment and airy the rest of the time. A plastic nursery pot of dense peat soil sitting in a dim corner of an air-conditioned house is close to the opposite of that.

When soil stays saturated, the air spaces between particles fill with water and the roots suffocate. Suffocating roots stop moving water and nutrients, and the plant responds by shutting down its oldest, cheapest leaves first: they turn a soft, even yellow, often starting at the bottom of the plant and working up. This is why yellowing and "overwatering" travel together, but the word overwatering is genuinely misleading. It is almost never about the volume of water in the can. It is about how often you water, how fast the pot drains, how big the pot is relative to the root ball, and how much light the plant has to drive water back out through its leaves. Change any one of those and the same amount of water becomes fine.

In this part of Florida there is a specific version of this I see constantly: a beautiful ceramic cachepot with no drainage hole, with the nursery pot dropped inside it. Every watering leaves an inch of water in the bottom that nobody sees. The plant sits in it for a week. If you own one of these, lift the plant out right now and look.

The other causes, roughly in the order I find them

• Not enough light. Distinct from the water problem but usually tangled with it. A monstera in low light drinks slowly, so the soil stays wet longer, so the roots suffocate. The tells are small new leaves with no splits, long bare stretches of stem between leaves, and the plant leaning hard toward the window. Bright indirect light is the target: within a few feet of a window, out of the direct midday beam.
• Running out of food. A monstera that has been in the same pot and the same soil for two or three years, growing the whole time, has used up what was in that soil. The yellowing here is different: it is spread across many older leaves at once, often pale and uniform, on a plant that is otherwise firm and rooted well. Feed lightly during active growth rather than heavily once.
• Root rot that is already established. The stage past wet roots. Stems soft near the soil line, a sour smell, roots that are brown or black and slide out of their sheath when pulled. This one does not fix itself by watering less, which is exactly what makes it worth its own page.
• Mineral salt buildup. A white crust on the soil surface or the pot rim. The minerals in hard tap water and the fertilizer you feed with are both salts, and in a pot that never drains freely they accumulate and burn root tips. Yellowing plus browning leaf edges together points here.
• Pests. Least common on monstera, but check anyway. Spider mites stipple leaves with fine pale dots and leave webbing in the leaf joints; mealybugs look like cotton lint where the petiole meets the stem. Both are easier to catch early than to argue with later.

How to tell them apart in ten minutes

• Push a finger two inches into the soil. Wet several days after watering, or wet at all if you cannot remember the last time you watered? Water problem. Dust dry all the way down with crispy edges on the leaves? The opposite problem, and much rarer.
• Lift the pot out of anything decorative. Standing water in the bottom answers the question by itself.
• Look at which leaves are yellowing. Oldest and lowest first, slowly, one at a time, with healthy new growth above: normal aging or mild hunger. Several at once, or newest growth affected: something is wrong now.
• Squeeze the stem at the soil line. Firm is good. Soft, squishy, or darkened means the rot has reached the stem and time matters.
• Turn a leaf over and look at the underside and the leaf joints in good light for webbing, cotton, or moving specks.

What to do this week

1. Empty any cachepot or saucer, and keep emptying it every time you water.
2. Stop watering on a schedule. Water when the top two inches are dry, then water thoroughly until it runs out the bottom.
3. Move the plant closer to a bright window, out of direct midday sun.
4. Remove leaves that are more yellow than green, cutting the petiole close to the main stem with clean scissors.
5. If the stem is soft or the soil smells sour, unpot it and look at the roots today, not next weekend.
6. Hold off on fertilizer until the plant is growing again. Feeding a plant with damaged roots adds salt to an already stressed system.

When to call me

Call if the stem is soft, if the plant has lost more than a third of its leaves, or if you have already changed the watering and it is still going backwards: those are the cases where guessing costs you the plant. A health diagnosis visit means I look at the roots, the soil, the pot, and the actual light in that room, and you get a written plan the same week. If it is one plant and you would rather not have anyone in the house, a virtual consult over video handles most monstera cases fine.

Related reading while you wait: the plant with almost exactly the same symptom pattern is pothos, and the thing you are ruling out is root rot.