Calandiva Disease Diagnosis: Bacterial Leaf Spot, Insect Damage, and Home Remedies

Black Spots, White Scars, and Brown Patches on Calandiva

Your white Calandiva shows progressive black leaf spots despite leaf removal, while the orange Calandiva has white stem scars and a few brown leaf spots. The black spots suggest a bacterial or fungal leaf spot; the white scars are likely slug or caterpillar feeding at night.

Treatment Protocol

1. Remove and destroy all affected leaves. Do not compost.
2. Spray Cornell fungicide: 1 tbsp baking soda + 1 tbsp light horticultural oil per gallon water. Apply every 3–4 days for three treatments.
3. Treat for insects: Apply Bayer Advanced Tree & Shrub Insecticide (imidacloprid) as a soil drench per label. Move plants outdoors overnight after application.
4. Adjust culture: Water at soil level, avoid wetting foliage, ensure good airflow.

Prognosis

Both plants can recover if the disease hasn’t invaded the crown. The orange Calandiva looks healthier and should respond quickly. Isolate from other succulents until symptoms resolve.