Cottonwood Fluff: Female Trees Produce It—Nothing Stops It

Annual Cottonwood "Snow" Is a Sex Thing

A homeowner loves their huge poplar/cottonwood but hates 6 weeks of white fluff clogging gutters. Can injection or treatment stop it?

Biology: Only Females Fluff

Cottonwoods (Populus deltoides and relatives) are dioecious—separate male/female trees. Fluff = seeds from females. Males produce pollen (allergenic) but no fluff.

No Medical Intervention Exists

You cannot change a tree's sex. No injection, spray, or treatment stops seed production without killing the tree. Growth regulators might reduce flowering but are impractical on large trees and unreliable.

Management Options

• Gutter guards: Mesh screens keep fluff out.
• Acceptance: Fluff lasts 2–3 weeks; it's a seasonal signature.
• Replacement (long-term): Plant male cultivar (e.g., 'Siouxland') if removing.

Reference

Wikipedia: en.wikipedia.org/wiki/Cottonwood