Sandpaper for Slug Control: Myth vs. Salt Barrier Reality

The Sandpaper Idea

Slugs avoid rough, abrasive surfaces, but sandpaper on pot rims is impractical—edges curl, lose grit, and slugs cross anyway.

What Actually Works: Salt Barriers

Rock salt creates an impassable osmotic barrier. In a test, slugs crossed every material (lava rock, sand, diatomaceous earth) except salt.

How to Build a Salt Barrier

1. Place pots on a patio or tray.
2. Create a 4-inch wide band of rock salt around the group.
3. Cover with a board "roof" to keep salt dry.
4. Replenish after rain.

Cautions

Salt contaminates soil—never use in garden beds. Safe only on impermeable surfaces.

On Sluggo (Iron Phosphate)

Contains EDTA (chelating agent). Not universally approved for organic use. Salt remains the most reliable, non-toxic (to soil) barrier for containers.