Poplar Leaf Blackening: Powdery Mildew Unlikely, Sanitation Key

Poplars in Southern Alberta have leaves turning black then brown and falling. Owner wonders if powdery mildew from a nearby caragana hedge spread. Expert says powdery mildew isn’t typical on caragana. If PM is suspected, get microscopic confirmation. PM causes premature defoliation but is usually cosmetic. Rake and destroy fallen leaves before spring to reduce spores.

Takeaway

• Don’t assume cross-infection without confirmation.
• Sanitation (leaf removal) is the best cultural practice.
• Consult local ag office for regional disease info.

Climate influences severity; monitor and clean up.