Yellow leaves on Corn plant most often point to a watering problem. On this plant, the first signs are often yellowing lower leaves and soft mushy cane. Check the causes below to find which one fits, then follow its fix.
Overwatering & root rot. Stop watering. Make sure the pot can actually drain, and wait until the top 5 cm of soil feel dry to the touch. Because this plant’s roots are delicate, unpot it at the first sign of a soft or sour-smelling crown rather than waiting.
What’s causing it
Tap-water minerals (a real trigger on this plant)
How to tell
Unlike most houseplants, Corn plant is genuinely sensitive to the salts and fluoride in ordinary tap water: a general, all-over yellowing with no soggy soil and no light problem often traces back to this rather than watering technique.
The fix
Switch to filtered, distilled, or rested rainwater, and flush the soil every few months to clear built-up minerals. Sensitive plants like this one often green back up within a few weeks of the switch.
Too little light
How to tell
The yellowing comes with dull, fading leaf patterning and pale new growth leaning toward the nearest window. Corn plant wants medium, indirect light. Together, those changes show that the spot is too dim.
The fix
Move it to a brighter spot. The patterning sharpens back up within a few new leaves, but keep it out of harsh midday sun, which scorches.
Thirst (underwatering)
How to tell
The soil is bone dry, and the yellowing arrives alongside brown leaf tips rather than soft, mushy growth.
The fix
Water thoroughly (every 6 to 8 days in summer is the usual pace for a Corn plant), then settle into feeling the soil before every watering rather than watering on a fixed day.
Hungry (nutrient shortfall, but easy to overcorrect)
How to tell
Older leaves fade evenly and growth has slowed after many months unfed, but this genus is also easily salt-burned by fertilizer, so don’t overcompensate.
The fix
Feed at a quarter to half the label strength through the growing season, flush the mix with plain water every couple of months, and refresh the top layer or repot if it’s been over a year.
Normal lower-leaf shedding
How to tell
A single lower leaf yellows and drops while the top keeps pushing new growth. Corn plant naturally sheds its oldest leaves as the cane grows taller.
The fix
Nothing is wrong. Snip the spent leaf off cleanly at the stem and carry on.
Prevention
Switch to filtered or rainwater since this plant is genuinely salt-sensitive, check the mix regularly rather than on a fixed schedule, and keep humidity up.