The soil is still wet days after watering, the lower and oldest leaves yellow first, and the stem base may feel soft. Small dark flies around moist potting medium may be fungus gnats. They suggest conditions suitable for breeding, without proving that the surface never dries.
The fix
Stop watering. Make sure the pot can actually drain, and wait until the top 5 cm (2 in) of soil feel dry to the touch. If the base is mushy or smells sour, unpot it and trim any brown, soft roots before repotting in fresh mix.
Other possible causes
Not a match? Compare the signs below to find the one you have.
Tap-water minerals (a real trigger on this plant)
How to tell
Dragon tree is more sensitive than most houseplants to the fluoride and salts in tap water. The sign is yellow or brown edges and tips that spread slowly inward, not an even yellowing of whole leaves. All-over yellowing points to watering, light or feeding instead, so check those first.
The fix
Water with rainwater or distilled water, and flush the soil every few months to clear built-up minerals. Damaged edges won’t turn green again, but new leaves should come in clean.
Too little light
How to tell
The yellowing comes with pale, stretched new growth leaning toward the nearest window. That combination shows that the spot is too dim for a dragon tree.
The fix
Move it to a brighter spot, 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 crispy leaf tips rather than soft, mushy growth.
The fix
If the soil is dry, water thoroughly (every 8 to 12 days in summer is the usual pace for a dragon tree), 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. Dragon tree 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.
