Diagnosing Persistent Drosera adelae Decline in Oregon

An Oregon grower (near Days Creek) has a 10-month-old D. adelae that never recovered from a 2-month dry period. A younger plant from the same source thrives. The older plant shows an odd brown/black protrusion at the base above small but healthy-looking roots. Currently in water culture like a thriving D. multifida extrema. East window, 70-75°F, distilled water, no artificial light.

Assessment

Root system is insufficient for a 10-month plant. The "protrusion" is part of the root crown. Abnormal leaf growth suggests pests (thrips are common on adelae and cause deformation). Thrips require magnification to see.

Recommendations

1. Light: East windows in PNW often have morning fog. Supplement with artificial light or move to south window. Fall/winter light will worsen.
2. Fertilizer: If fertilizing, stop. D. adelae is sensitive; only very weak solutions tolerated.
3. Pests: Spray with systemic insecticide (only way to eliminate thrips). Watch our insecticide video: YouTube link

Prognosis

If no insecticide available, discard plant to protect collection. Recovery would take many months even with treatment. The root system and leaf canopy are too compromised for reliable comeback.