Azalea Leaf Browning: Environmental, Not Insect or Disease

Azalea leaves have geographic brown patches with fine white surface on upper leaf. What is this?

No Pests/Pathogens Visible

Pattern suggests abiotic stress:

• Water extremes (too much/little)
• Nutrient imbalance
• Soil pH too high—azaleas need 4.5–6.0

Action Plan

1. Soil test for pH and nutrients
2. Acidify if needed (sulfur, iron sulfate)
3. Azalea/camellia fertilizer (acid-forming)
4. Mulch with pine bark/straw

May be late for this season, but sets up next spring.