Specialty Gardening: Container Soils and Water Movement in Containers (long post), 0 by tapla

tapla wrote:
I'm not sure. The common name "Cedar" covers much ground and includes trees in at least 7 genera I can think of just off the top of my head. You'd need to find out what tree the bark came from and research it for any allelopathic properties (poisonous to plants - like some trees in the Juglans genus). Wish I could help more.

Mixing some diatomaceous earth into a damp soil as you make it would also solve your carpenter ant problem so you could use the pine bark.

There's a wide range of particle sizes that are appropriate. I use the bark at both 3 and 9 o'clock for many soils, but for veggies and flowery display containers, I prefer a product that looks like what's at 12 o'clock.