The yellow film coating your windows every spring isn't what's making you sneeze

Every spring, a yellow-green film settles over cars, patios, and windows across Florida, and most of it is pine pollen — slash pines are especially heavy producers. Unlike the microscopic, airborne pollen that actually triggers allergies, this visible dust is large, tacky, and heavy enough to fall out of the air within hours of release, which is exactly why it's so easy to see coating a flat surface.

That visible film isn't harmless, though. Pine pollen runs acidic, with a pH in the 4.0 to 5.5 range, and if it's left to sit on glass, siding, or concrete it can stain and, on paint or glass, etch. In much of Florida the season starts earlier than up north — visible dust can show up as early as January in the southern part of the state and typically runs through spring.