Drosera filiformis Blackening: Dormancy or Root Heat Stress?

Jiung in southern Michigan reported a threadleaf sundew (2 months old, pure sphagnum, 6 hrs direct sun, tray watering with distilled water) developing black, dead-looking new leaves after rainy, windy weather.

Two Leading Theories

1. Natural dormancy onset: Depending on the strain's geographic origin and spring emergence timing, some D. filiformis (especially D. × hybrida from New Jersey) begin forming hibernacula (winter buds) in late summer.
2. Root overheating in clear saucer/net pot: Clear saucers act like mini-greenhouses, heating water to root-damaging temperatures. Net pots expose roots to air—D. filiformis isn't an epiphyte. Switch to opaque saucer and standard pot.

Long-Term Fix

Sow fresh seed this fall in multiple pots, leave outdoors for winter. Spring germination yields abundant plants.

Good Growing!
Jeff Dallas
Sarracenia Northwest
www.growcarnivorousplants.com