Diatomaceous Earth vs Kaolin Clay
| Feature | Diatomaceous Earth (DE) | Kaolin Clay (Surround) |
|---|---|---|
| Tier | Tier A | Tier B |
| Type | Mineral / Physical | Mineral / Physical barrier |
| Safety | Safe | Safe |
| Bee Safe | ✓ Yes | ✓ Yes |
| Pet Safe | ✓ Yes | ✓ Yes |
| OMRI Listed | ✓ Yes | ✓ Yes |
| Residual | Effective as long as it stays dry; loses effectiveness when wet | Lasts until washed off by rain; reapply after heavy rainfall |
| Best For | Crawling insects in dry conditions. Perimeter barriers around raised beds. Slug deterrent rings around plants. | Fruit tree protection during pest flight season. Preventive barrier before pest arrival. |
Verdict
DE for ground-level crawlers in dry conditions; kaolin for plant surface barriers. Different applications entirely.
Full Guide: Diatomaceous Earth (DE)
Diatomaceous earth kills crawling insects through physical abrasion and desiccation — no chemical action means no resistance development is possible. Food-grade DE is safe for organic gardens but only works in dry conditions.
Full Guide: Kaolin Clay (Surround)
Kaolin clay creates a white particle film on plant surfaces that irritates insects, blocks egg-laying, and makes plants unrecognizable to pests. It does not kill — it creates a physical barrier that deters beetles, moths, and aphids before they establish.