Gray Mold (Botrytis Blight): Urgent! How to Save Your Plant
Gray mold, caused by the fungus Botrytis cinerea, is one of the most common fungal diseases in plants. It affects over 200 plant species, including ornamentals, vegetables, fruits, and houseplants. The disease thrives in cool, humid conditions with poor air circulation, causing grayish spots and soft rot on infected tissues.
Fast
14 days
🔍 Symptoms
Main Symptoms
- ! Grayish colored soft, mushy spots on leaves, stems, and flowers
- ! Gray fuzzy coating of fungal spores, especially in high humidity
- ! Brown to gray circular spots on leaves and petals
- ! Shriveled and rotted fruit or plant parts
- ! Black, stone-like sclerotia under rotted parts
- ! Water-soaked lesions that expand rapidly
- ! Wilting and collapse of affected tissues
Visual Signs
❓ Possible Causes
- → High humidity (above 85%) combined with moderate temperatures (64-73°F/18-23°C)
- → Poor air circulation around plants
- → Overwatering or standing water on foliage
- → Dense plantings with inadequate spacing
- → Damaged or stressed plant tissues
- → Dead flowers and leaves not removed
- → Low light conditions
💊 Treatment
Quick Fixes
~7 days
Remove and dispose of all visibly infected parts
Remove and dispose of all visibly infected parts
Isolate plant from other healthy plants
Isolate plant from other healthy plants
Apply chemical fungicide (Captan or Chlorothalonil) following instructions
Apply chemical fungicide (Captan or Chlorothalonil) following instructions
Reapply fungicide
Reapply fungicide
Third fungicide application
Third fungicide application
Assess improvement and continue if needed
Assess improvement and continue if needed
Materials needed:
Organic Treatment
~14 days
Remove all infected parts with clean pruners and dispose in plastic bag
Remove all infected parts with clean pruners and dispose in plastic bag
Improve ventilation and reduce plant density
Improve ventilation and reduce plant density
Apply baking soda spray (1 tbsp/quart) to entire plant
Apply baking soda spray (1 tbsp/quart) to entire plant
Apply neem oil to foliage (morning or late afternoon)
Apply neem oil to foliage (morning or late afternoon)
Reapply baking soda spray
Reapply baking soda spray
Apply Bacillus subtilis as biofungicide
Apply Bacillus subtilis as biofungicide
Complete inspection and removal of new spots
Complete inspection and removal of new spots
Final assessment and preventive maintenance
Final assessment and preventive maintenance
Materials needed:
Expert Treatment
~21 days
Assess infection extent and identify contributing environmental factors
Assess infection extent and identify contributing environmental factors
Surgical removal of infected tissues with 2-3cm safety margin
Surgical removal of infected tissues with 2-3cm safety margin
Correct environmental conditions: increase ventilation, reduce humidity (<85%)
Correct environmental conditions: increase ventilation, reduce humidity (<85%)
Apply systemic fungicide (Iprodione or Fenhexamid)
Apply systemic fungicide (Iprodione or Fenhexamid)
Foliar spray with contact fungicide (Captan)
Foliar spray with contact fungicide (Captan)
Reapply systemic fungicide
Reapply systemic fungicide
Alternate with biofungicide (Bacillus subtilis) to prevent resistance
Alternate with biofungicide (Bacillus subtilis) to prevent resistance
Apply preventive contact fungicide
Apply preventive contact fungicide
Final systemic fungicide application
Final systemic fungicide application
Final assessment and monthly preventive maintenance program
Final assessment and monthly preventive maintenance program
Step by Step
- 1
Inspect plants regularly for early signs
- 2
Immediately remove all infected parts with sterilized pruners
- 3
Place infected material in sealed plastic bag and dispose in trash
- 4
Improve air circulation by reducing density and increasing ventilation
- 5
Reduce humidity and avoid wetting foliage
- 6
Apply organic or chemical preventive treatment to adjacent plants
- 7
Disinfect pruning tools after each use
- 8
Continue monitoring for 2-3 weeks after treatment
🧪 Solutions
🌱 Natural Solutions
- ✓ Immediate pruning of infected parts (use plastic bags for disposal)
- ✓ Baking soda spray (1 tablespoon per quart of water)
- ✓ Neem oil application (follow label instructions)
- ✓ Organic copper spray as preventive
- ✓ Aerated compost tea applied to foliage
- ✓ Milk solution (1 part milk to 9 parts water)
- ✓ Garlic extract as natural fungicide
- ✓ Bacillus subtilis (biofungicide)
💉 Chemical Solutions
- ✓ Copper-based fungicides (copper sulfate, copper hydroxide)
- ✓ Captan (contact fungicide)
- ✓ Chlorothalonil (preventive)
- ✓ Iprodione (systemic)
- ✓ Fenhexamid (Botrytis-specific)
- ✓ Pyrimethanil (systemic)
🛡️ Prevention
- ✓ Maintain good air circulation with adequate plant spacing
- ✓ Avoid overhead watering; use drip irrigation or water at base
- ✓ Remove wilted flowers and fallen leaves immediately
- ✓ Water in the morning to allow foliage to dry during the day
- ✓ Use mulch to prevent soil-borne spores from splashing
- ✓ Keep relative humidity below 85%
- ✓ Improve ventilation in greenhouses and indoor spaces
- ✓ Avoid excessive nitrogen fertilization
