Sunburn
Consider scorch when patches follow an increase in sun and mainly affect exposed surfaces. That is a clue, not proof. ZZ does not lack all protective pigments; a shade-grown plant can simply be poorly acclimatised to intense light.
Filter harsh sun while retaining useful daylight. Photograph patches and monitor new damage. Dead tissue will not repair itself, and continuing spread deserves a broader check of roots, pests and temperature.
Low humidity
ZZ generally tolerates ordinary household humidity. Brown tips alone are not a reason to buy a humidifier. Review drying, roots, feeding and nearby hot air first; measure conditions if unusually dry air remains a concern.
Fertilizer or mineral salt buildup
Check feed dose and any deposits, but do not treat evenly brown tips as a conclusive salt test. Pause extra feed while investigating. Leaching can help a freely draining pot; repeated flushing of saturated mix with damaged roots may worsen conditions.
Physical damage
An isolated scuffed, bruised, or discolored patch on a single leaflet — from a knock, a graze while moving the plant, or pressure against a wall — can look superficially similar to early sunburn but stays confined to that one spot rather than following the light-facing pattern.
Fix: nothing needed for the plant's overall health. Trim the affected leaflet if you'd like a tidier look, or leave it.
Keep a short care record
Photograph the whole plant and any damage, and note moisture checks and recent changes. Compare later growth rather than expecting an old scar to disappear. Continuing collapse, expanding lesions or extensive decay deserves specialist help.
Reference material
Reference material consulted for this independently written guide. The publishers listed have not reviewed or endorsed it.
- NC State Extension — ZZ plant
- University of Maryland — watering
- University of Maryland — symptom checks