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Why "Cottonless" Cottonwood Is Producing Cotton

The Truth About Cottonless Cottonwoods

If your 11-year-old "cottonless" cottonwoods are suddenly producing cottony seeds, there's a simple explanation: you have female trees.

Cottonwood Biology

Cottonwoods are dioecious—separate male and female trees. Only females produce the cottony seeds. Nurseries sell "cottonless" varieties by propagating male clones, but sometimes:

Trees are mislabeled
A tree labeled male is actually female
Seed production begins at maturity (around 10-15 years)

Can You Stop the Cotton?

A growth regulator called Florel® (ethephon) can reduce or eliminate seed production when applied just before flowering. However:

Timing is critical and region-specific
Professional application with proper equipment is recommended
Treatment must be repeated annually

Long-Term Options

If cotton production is intolerable, consider replacing female trees with verified male cultivars like 'Siouxland' or 'Robusta.' Consult a certified arborist for Florel application or replacement planning.

Trees: Identifying and Managing Slime Flux (Bacterial Wetwood) in Mature Cottonwoods; Planting Magnolia Seeds from Frozen Cones: Low Viability, But Try; Cottonwood Leaf Rust: Yellow Spots and Early Leaf Drop; Cottonless Cottonwood Stump Sprouts: Glyphosate Control; Overwatering Kills Young Cottonless Cottonwood; Cottonless Cottonwood Sparse Foliage: First-Year Root Establishment; Cottonwood Honeydew Crisis: Aphid/Scale Control on Mature Tree; Cottonless Cottonwood Transplant Failure: Diagnosis and Replacement; Cottonwood Seed Management: Florel Growth Regulator for Cotton Control; Cottonless Cottonwood Leaf Rust: One Tree Affected, One Healthy

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