Venus Flytrap Dying? Tap Water and Dormancy Are Likely Culprits

A new flytrap owner reported blackening leaves, traps that wouldn't close, and new growth dying back—all while using tap water and keeping the plant on a kitchen windowsill.

Primary Suspect: Tap Water

Most municipal water has >50 ppm dissolved minerals (hardness). Calcium and magnesium accumulate, raising soil pH and burning roots. Death typically occurs within months. Test your water hardness. If >50 ppm, switch immediately to rain, distilled, or RO water.

Secondary Issue: Missing Dormancy

Venus flytraps are temperate perennials, not tropical. They require a cold winter dormancy (35–50°F, short days) to survive long-term. A warm kitchen window prevents dormancy, leading to weak, etiolated growth and eventual exhaustion.

Immediate Steps

1. Stop tap water. Use pure water only.
2. If winter, place plant in an unheated garage, cold frame, or refrigerator (wrapped in damp sphagnum) for 3–4 months.
3. If growing season, move outdoors to full sun with tray watering.

Correct water and dormancy are non-negotiable for healthy flytraps.