Poison Ivy Galls: Identification and Safe Removal

Those Bushy Growths Are Likely Galls

Green, leafy clumps on poison ivy (Toxicodendron radicans) in New Jersey that persist as fibrous masses in winter are almost certainly insect-induced galls—not lichens or aborted flowers. Common culprits:

• Poison ivy gall mite (Aculops toxicophagus): causes dense, hairy, broom-like growths ( erineum galls) on leaf undersides and stems
• Gall-making aphids (Melaphis spp.): induce pouch or bladder galls on leaves
• Cynipid wasps: various stem and leaf galls

Ecological Note

These galls house developing insects but don't significantly harm the vine. Poison ivy's legendary vigor tolerates galling easily. The galls themselves are not urushiol-bearing (the oil is in leaves, stems, roots), but handling galled vines risks contact with adjacent foliage.

Management: Focus on the Vine, Not the Galls

No gall-specific treatment needed. The insects are protected inside; sprays won't reach them. Instead, manage the poison ivy itself:

• Herbicide: Triclopyr (Brush-B-Gon, Garlon) or glyphosate (Roundup) + surfactant applied to actively growing foliage (late spring–early fall). Cut-stump treatment for large vines.
• Manual: Pull/dig with full PPE (disposable coveralls, heavy gloves, goggles). Bag all material. Never burn—urushiol in smoke causes severe respiratory injury.
• Timing: Treat after full leaf-out but before fall color for best translocation.

Safety First

If you're sensitive, hire a professional. Wash tools with Tecnu or rubbing alcohol. Launder clothing separately. The galls are a curiosity; the vine is the hazard.