White Fluff on Live Oak: Powdery Mildew or Woolly Aphids?

Live oak suddenly covered in white, lint-like growth on leaves/branches. Two likely causes:

1. Woolly Oak Aphid

• Fluff moves if touched; sticky honeydew present.
• Small, waxy insects on leaf undersides/twigs.
• Treat: systemic imidacloprid soil drench (Bayer Advanced) or contact sprays (acephate, bifenthrin, neem).

2. Powdery Mildew

• Fluff static; powdery, not waxy.
• Fungal; favors humidity, shade.
• Treat: rotate fungicides (sulfur, neem oil, triadimefon, etc.) per label.

Diagnosis Tip

Touch the fluff. If it moves → aphids. If not → mildew. Large trees need soil-applied systemic for aphids; mildew often resolves with better air flow.