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Sunflower Allelopathy: Seed Hulls Inhibit Other Plants

Allelopathy = one plant chemically inhibits another. Sunflower seed hulls under feeders suppress growth; effect fades in two months. Roots may not be allelopathic.

Planting Advice

Space sunflowers 16 inches apart. Remove stems and roots each fall to minimize residue buildup.

About Gardening: Sunflower Diseases: 9 Common Ones; Dealing with Tree Roots in the Lawn: Removal and Prevention; Tree Roots Lifting Pavers: Switch to Gravel or Raise Patio; Conifer Roots in Lawn: Managing Surface Roots Without Harming Trees; What Is a Tree's Dripline? The Key Zone for Watering and Mulching; Exposed Oak Roots Along Driveway: Normal, Mulch for Safety; Lantana Allelopathy: Temporary Effect on Nearby Plants; Exposed Maple Roots: Mulch, Don't Bury; Junipers Won't Re-Sprout on Bare Stems—Here's What to Do Instead; Tree Roots Invading Your Compost Pile? Here's the Simple Fix

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