Reviving a Declining ZZ Plant (Zamioculcas zamiifolia)

A ZZ plant down to one stem shows curling, yellowing leaves and stem death despite "neglect" watering. Likely cause: pot too large, soil staying moist, causing root rot or root mealybugs. ZZ plants prefer being root-bound and very dry.

Unpot, trim dead roots (healthy are white, plump), and repot the single stem in a much smaller pot with slightly moist, well-draining soil. Water only every 3 weeks in bright light, monthly in low light. The "neglect" may still be too much water for this drought-adapted species.

If roots are rotted or mealybugs present, the plant may be unsalvageable. But a fresh start in a tight pot with strict drought often works miracles.