If there's one thing that kills more potted melastomes than anything else, it's watering — and specifically, watering on a fixed schedule rather than in response to what the plant and soil actually need. A weekly watering routine feels organized, but it ignores that water needs shift constantly with temperature, humidity, pot size, and season.
The overwatering habit
Melastomataceae generally wants consistently moist soil, and that phrase gets misread as "always wet" more often than it should. Constantly saturated soil starves roots of oxygen and invites the kind of root rot that shows up later as yellowing leaves and a generally unhappy plant, by which point the damage is already underway. The better test is to check the top few centimeters of soil before watering — if it's still damp, wait.
The underwatering habit
The opposite mistake shows up mostly in hot, dry conditions or with plants that have outgrown their pot and dry out faster than expected. Melastomes wilt visibly and recover once watered, which trains some growers into a boom-and-bust cycle — letting the plant droop before watering, rather than watering before it gets that stressed. Occasional wilting won't kill a mature plant, but repeated cycles of it weaken root systems over time and show up as reduced flowering.
Water quality matters more than people expect
Because this family prefers acidic soil, consistently hard or alkaline tap water is a slower, less obvious problem — it gradually pushes soil pH upward over months, showing up eventually as the interveinal yellowing that's easy to misdiagnose as a totally separate issue. Rainwater or filtered water is worth the extra effort for anyone in a hard-water area who's fighting recurring, hard-to-explain yellowing despite an otherwise reasonable watering routine.