Troubleshooting
Curly Oncidium problems — and how to fix them
Curly Oncidium (Oncidium crispum) is generally forgiving once you match its basics, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Pseudobulb shrivelling during growth
Shrivelling outside the rest period indicates inadequate root function — either from rot, insufficient watering, or a medium that has broken down and is hydrophobic. Unpot, inspect and trim damaged roots, refresh the bark medium, and water consistently during active growth.
Black rot (Phytophthora or Pythium)
Rapid blackening at the base of new growths or pseudobulbs indicates bacterial or fungal rot, often triggered by overwatering in cool conditions. Remove affected tissue with a sterile blade, treat with a systemic fungicide, and improve drainage and air circulation.
Thrips causing flower distortion
Thrips feed on developing buds and cause silvery streaking or distorted petals when flowers open. Treat emerging spikes with a systemic insecticide or spinosad-based spray. Yellow sticky traps near the plant help monitor populations.
Prevent curly oncidium problems before they start
Most curly oncidium issues are care-mismatch, not bad luck. Dial in the basics:
Looking for curly oncidium in general rather than its problems? Read the full curly oncidium care guide — light, water, soil and feeding.
Curly Oncidium problems — FAQ
Why is my curly oncidium pseudobulb shrivelling during growth?
Shrivelling outside the rest period indicates inadequate root function — either from rot, insufficient watering, or a medium that has broken down and is hydrophobic. Unpot, inspect and trim damaged roots, refresh the bark medium, and water consistently during active growth.
Why is my curly oncidium black rot (phytophthora or pythium)?
Rapid blackening at the base of new growths or pseudobulbs indicates bacterial or fungal rot, often triggered by overwatering in cool conditions. Remove affected tissue with a sterile blade, treat with a systemic fungicide, and improve drainage and air circulation.
Why is my curly oncidium thrips causing flower distortion?
Thrips feed on developing buds and cause silvery streaking or distorted petals when flowers open. Treat emerging spikes with a systemic insecticide or spinosad-based spray. Yellow sticky traps near the plant help monitor populations.