Powdery Mildew on New Squash Plant: Return It, Don't Treat

New squash plant has powdery mildew on leaves and stems. Asks if neem oil will cure or should return to nursery.

Answer: Return It Immediately

• Buying a diseased plant introduces spores to your garden.
• Neem oil / baking soda spray can suppress but not eradicate established infection.
• Plant may be permanently stunted.

If You Must Treat (Not Recommended)

• Baking soda: 1 Tbsp/gallon water + 1 tsp horticultural oil. Spray weekly.
• Neem oil per label.
• Remove all affected leaves first.

Prevention for Future

• Inspect plants before purchase.
• Space for air flow.
• Water at soil level, not foliage.
• Choose resistant varieties (e.g., 'Dunja', 'Success PM').

Don't nurse a sick start—exchange for a healthy plant.