African Spear with Powdery Mildew? Rare but Treatable
Sansevieria cylindrica
Powdery mildew is a common fungal disease caused by various fungi species including Erysiphe, Podosphaera, Oïdium, and Leveillula. It affects over 10,000 plant species worldwide. The disease thrives in warm, dry climates with high humidity and appears as a distinctive white powdery coating on plant surfaces.
🔍 Symptoms
- • White to gray powdery spots on leaves, stems, and buds
- • Flour-like coating on plant surfaces
- • Purple to red discoloration around infected areas
- • Distorted or twisted young leaves
- • Early wilting and leaf browning
- • Reduced plant growth and flowering
- • Leaf rolling and curled shoots
- • Scab-like sores on severe infections
❓ Possible Causes
- → Fungal spores carried by wind from infected plants
- → Warm temperatures (60-80°F / 15-27°C)
- → High relative humidity around plants
- → Poor air circulation and shaded areas
- → Over-fertilization making plants susceptible
- → Spores overwintering on crop residue and weeds
💊 Treatment
Quick Fixes
Remove heavily infected areas
Cut away all heavily infected plant parts. Dispose properly away from garden.
Apply potassium bicarbonate
Mix according to product instructions. Spray thoroughly covering all plant surfaces. Wear protective gloves.
Second application
Reapply potassium bicarbonate fungicide after 3 days for enhanced effectiveness.
Switch to sulfur spray
Apply sulfur-based fungicide. Avoid using in temperatures above 80°F to prevent plant damage.
Continue sulfur treatment
Apply second sulfur treatment. Monitor for significant improvement in plant health.
Final treatment and assessment
Apply final treatment. Disease should be under control. Monitor weekly for recurrence.
Organic Treatment
Remove infected parts
Use sterilized pruning shears to cut off all leaves, stems, and buds showing white powdery coating. Dispose in trash, not compost.
Prepare organic spray
Mix 1 tablespoon potassium bicarbonate (or baking soda) with ½ teaspoon Castile soap in 1 gallon of water. Shake well.
Apply first treatment
Spray solution thoroughly on all leaf surfaces (top and bottom), stems, and surrounding foliage. Apply in early morning or evening.
Weekly treatment - Week 1
Prepare fresh solution and spray all plant surfaces again. Check for new infections and remove any affected parts.
Weekly treatment - Week 2
Continue weekly spraying. Monitor plant response and adjust spacing if needed for better airflow.
Weekly treatment - Week 3
Apply fourth treatment. Disease should be significantly reduced by now.
Final treatment and evaluation
Apply final treatment. Evaluate effectiveness. If infection persists, consider chemical options or continue weekly for 2 more weeks.
🛡️ Prevention
- ✓ Choose powdery mildew-resistant plant varieties
- ✓ Maintain adequate spacing between plants for airflow
- ✓ Ensure plants receive sufficient sunlight
- ✓ Avoid over-fertilization with nitrogen-rich fertilizers
- ✓ Remove infected plant debris immediately
- ✓ Spray leaves with water in the morning to wash away spores
- ✓ Thin dense plant growth to improve air circulation
- ✓ Keep plants at reasonable distance from structures
🌱 Care Guide: African Spear
💧 How to Water
Water every 2 weeks in spring/summer and only once a month in fall/winter. Allow the soil to dry completely between waterings. Use the "soak and dry" method.
☀️ Lighting
Adapts well to low light conditions but thrives in bright indirect light. Tolerates direct sun, but too intense light may yellow the tips.
🪴 Ideal Soil
Use well-draining substrate with pH between 6-7. Ideal mix: potting soil, sand, and perlite in equal parts. Avoid waterlogged soil.