Yes, you can add diatomaceous earth compost bins safely when you do it the right way. The moist environment inside your pile neutralizes DE's pest control action. Your beneficial decomposers stay safe while DE controls pests around the outside.
I use DE around my compost bins to control fruit flies and ants that gather near the edges. The powder keeps pests from setting up home around the bin without hurting the worms and microbes inside. This approach has worked well for me for several years now.
The science explains why adding DE to compost is safe for your pile. DE needs to stay dry to work its pest control action. The moist interior of active compost keeps DE inactive. Your bacteria, fungi, and earthworms stay healthy and keep breaking down organic material.
Research shows that DE does not harm the organisms that drive your composting process at all. Microbes and fungi are too small and wet for DE to affect them in any way. Earthworms have a mucus coating that protects them from the drying action that kills insects.
The best way to use DE in compost pile areas is on the outside, not mixed throughout. Dust the dry surfaces around your bin to keep ants and flies away. This creates a pest barrier while leaving your active compost untouched inside.
I tested mixing DE into my pile one season to see what would happen. The compost broke down at the same rate as my untreated bin. Worm counts stayed the same in both piles after the full composting cycle finished up.
For compost pest control DE works best as a perimeter treatment around your bin. Dust a thin line around the base of your bin and on any dry surfaces you can find nearby. Reapply after rain since moisture stops DE from working on the pests you want to control.
Avoid heavy application of DE to the active moist center of your pile. While it will not hurt anything, it also will not help with pest control there. Save your product for the dry edges where pests crawl.
Adding DE to compost is safe for your pile and helpful for pest control around it. Keep DE on dry surfaces outside the bin. Protect your beneficial helpers inside the pile. Reapply when rain washes your barriers away. Your compost and your pest control will work together well all season long.
Read the full article: Diatomaceous Earth Garden: Complete Guide
