What are the white spots on my plant?
Three unrelated things look white on a leaf, and the test is simply whether it wipes off.
The causes, and how to tell them apart
Mealybugs common
How to tell: White cottony tufts tucked into leaf joints and undersides. They wipe off and are slightly sticky. Often with sticky residue on leaves below.
What to do: Dab each one with a cotton swab dipped in 70% isopropyl alcohol, then treat with insecticidal soap weekly for four weeks — they hide in the soil and crown and come back from a single missed one.
Powdery mildew common in still air
How to tell: A dusty white coating spread flat across the leaf SURFACE, like flour. Does not wipe off cleanly.
What to do: Improve airflow, stop wetting the foliage, remove the worst leaves, and space plants further apart.
Mineral deposits from hard water harmless
How to tell: Chalky white flecks or a crust, often also on the pot rim and soil surface. Wipes off with a damp cloth.
What to do: Cosmetic only. Wipe the leaves; switch to filtered or distilled water if it bothers you.
Plantroster compares this month's photo against last month's, so slow changes — the ones you stop noticing because you see the plant every day — get flagged.
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General horticultural guidance, not a diagnosis of your specific plant.