Why the smell?

Sweats after rain.

The smell is from the mulch composting in the bag. Once it hits the air the smell will go away in a few days. Thanks!

Did the mulch become wet before you purchased it or when you owned it during the time you stored it. If it became wet in the bags, it could have mildewed or molded. That would account for a musty bad smell. Several bags we had did that, I washed the chips off on a concrete slab and then allowed them to dry in the sun--that kills mildew and eliminates the musty smell. After sunning in the South Louisiana sun for a day there was no longer a smell and I put them out as I did other bags. I did not have any smell, other than a slight woodsy smell, that fresh chipped or cut wood would have in other bags. I still have 30 bags I purchased at the discounted price of $2 per bag and I am going to use several more bags to top off several flower beds but the most of the remainder will cover my new shade bed under my hostas and other shade plants and flowers.

it last a few days and typically after it's out of the bag and it's rained once or twice the smell is gone. I am very sensitive to smells and I haven't noticed it since we put the mulch in our flower beds a few days ago.