This is what Al says:

I haven't used cedar mulch to grow in,
so I can't comment on that practice directly, but I can say that because
the tannins, as well as terpenoid and phenolic compounds cedar is rich
in are known to be allelopathic (inhibit growth) to many other plants, I
have discounted the likelihood that it would be a suitable choice for
me.

Al

Heruga, I posted this in your other thread, but here it is again: Zoo Med Reptile Bark Fir Bedding, 24 Quarts https://www.amazon.com/dp/B001F9AMW6/ref=cm_sw_r_cp_api_XwrnybEF8CHWV

It is easy and works perfectly in the 5-1-1. Many of us here use it.

Doesn't FWG ship their trees in cedar mulch?

Cedar mulch is fine. As long as it is mulch, you won't have issues.

I would say it depends on what the "mulch" looks like. You need nuggets, not shavings, as the nuggets offer the shape and texture and durability the potting mix requires. Shavings will break down too rapidly.

If not able to locate the reptile bedding available at just about any pet store, fine orchid bark works equally as well. Both are perfectly viable substitutes for the pine bark and I would favor either of them over a cedar shaving mulch.

I hear it was redwood they use. Farmed but redwood.