Green onions Prone to White Mold: How to Protect
Allium fistulosum
White Mold on Green onions: What to Know?
White Mold on Green onions (Allium fistulosum) is a fungal condition with high severity. Green onions has high susceptibility to this disease. White mold (Sclerotinia sclerotiorum) is a devastating fungal disease affecting over 400 plant species worldwide. The fungus produces black, seed-like structures (sclerotia) that can survive in soil f...
Green onions is a easy-care plant. Recovery from White Mold takes approximately 21 days with proper treatment.
Green onions is highly susceptible to White Mold, unlike most plants in the same family. Without early intervention, recovery takes 32 days instead of 21 days. Unlike bacterial infections, White Mold on Green onions can be managed with organic fungicides. Without precautions, chemical treatments for White Mold can be harmful to pets. Use organic methods for Green onions in pet-friendly homes.
ð What Does White Mold Look Like on Green onions?
- âĒ Sudden wilting and yellowing of leaves
- âĒ Fluffy white mold growth on stems and leaves
- âĒ Water-soaked lesions expanding irregularly
- âĒ Soft, watery rot near soil level
- âĒ Black sclerotia (0.5-1cm) in white fungal mass
- âĒ Grayish-green appearance before wilting
- âĒ Infected stem sections become brittle and tan-colored
â What Causes White Mold on Green onions?
- â Fungus Sclerotinia sclerotiorum surviving in soil via sclerotia
- â Prolonged cool, moist conditions (50-68°F/10-20°C)
- â High humidity during flowering period
- â Poor air circulation from dense planting
- â Wind-borne spores from germinated sclerotia
- â Direct contact with contaminated soil
- â Fungus survival on plant debris for 5+ years
ð How to Treat White Mold on Green onions?
TLDR: Treat White Mold on Green onions with quick treatment (~11 days) or organic (~21 days). Green onions has high susceptibility to this disease.
Quick Fixes
Immediate removal
Remove and completely destroy all infected plants. Burn or bag and dispose in trash.
Apply fungicide
Apply systemic fungicide (SDHI or DMI) to neighboring healthy plants preventively.
Reduce moisture
Stop all overhead watering. Use drip only. Improve ventilation/drainage.
Isolate area
Create buffer zone by removing plants within 20-inch radius of infection.
Intensive monitoring
Inspect remaining plants 2x daily for 14 days.
Organic Treatment
Remove infected plants
Carefully remove entire plant without spreading sclerotia. Burn or bury deeply (24+ inches). Do not compost.
Apply biocontrol
Apply Coniothyrium minitans to soil per instructions. This fungus parasitizes Sclerotinia sclerotia.
Improve circulation
Thin adjacent plants to improve airflow. Space plants 12-18 inches apart.
Adjust irrigation
Switch to drip irrigation. Water early morning. Avoid wetting foliage.
Soil solarization
If possible, cover soil with clear plastic for 4-6 weeks in summer (kills sclerotia).
Monitoring
Inspect plants daily for 3 weeks. Remove any new infection immediately.
ðĄïļ How to Prevent White Mold on Green onions?
TLDR: Prevent White Mold on Green onions with 8 essential preventive care practices.
- â Plant with proper spacing to promote air circulation
- â Avoid excessive irrigation during and after flowering
- â Use drip irrigation instead of overhead sprinklers
- â Remove and destroy infected plants immediately
- â Implement crop rotation with 2-3 years of non-host crops (cereals, corn)
- â Water early in day so foliage dries before nightfall
- â Clean up all crop debris after harvest
- â Avoid planting susceptible species in areas with disease history
ðą How to Care for Green onions to Prevent White Mold?
ð§ How to Water
Water whenever the soil surface is dry to the touch, but avoid waterlogging to prevent root rot.
âïļ Lighting
For vigorous growth and crunchy leaves, green onions should receive at least 6 hours of direct sunlight per day.
ðŠī Ideal Soil
Use a mixture of potting soil with earthworm castings to ensure the necessary nutrients.
Frequently asked questions
Can White Mold kill my Green onions?
How long does Green onions take to recover from White Mold?
Is White Mold contagious to other plants near Green onions?
Sources & References
- Sclerotinia disease: Symptoms & Control | RHS Advice
- White mold in the garden | UMN Extension
- Sclerotinia sclerotiorum - Wikipedia
- White mold (Sclerotinia) | APS
- White Mold â Wisconsin Horticulture
- Missouri Botanical Garden â Allium fistulosum
- Gardenia.net â Allium fistulosum Bunching Onion
- Plantiary â Allium fistulosum care
- Morning Chores â 13 Common Allium Plant Pests and Diseases
- MOFGA â Foliar Diseases of Alliums