Pine bark is more acid (lower pH ... sold to commercial growers and potting soil manufacturers in bulk. Mulch processors sell fines by the semi load to growers and potting soil manufacturers.

Composted hardwood bark is an excellent mulch choice for the Northeast, while pine straw and pine fines are ideal for the Southeast. Softwood bark mulch, similar to pine fines but slightly larger ...

Mulch can be almost any loose aggregate material that will stay put and not significantly reduce air exchange out of the soil ...