Most fungus is not harmful. Especially after being a year old.

Many tree problems are associated with the following:

Troubles in the Rhizosphere
http://www.treedictionary.com/DICT2003/shigo/RHIZO.html

Unhealthy Trees from the Nursery / Improper Planting
http://home.ccil.org/~treeman/sub1.html and
Look up "Tree Planting"
http://www.treedictionary.com/DICT2003/shigo/RHIZO.html

Improper Mulching - http://home.ccil.org/~treeman/sub3.html and
http://www.treedictionary.com/DICT2003/M/index.html Look up "Mulch"

Improper Pruning
http://www.treedictionary.com/DICT2003/tree_pruning/

Improper Fertilization (See A Touch of Chemistry)
http://www.treedictionary.com/DICT2003/shigo/CHEM.html

Sincerely,
John A. Keslick, Jr.
Arborist
http://home.ccil.org/~treeman
and www.treedictionary.com
Beware of so-called tree experts who do not understand tree biology.
Storms, fires, floods, earthquakes, and volcanic eruptions keep reminding us
that we are not the boss.

"Mike S." wrote in message
ups.com...
My bag of mulch has white specks in it that looks like powder. I don't
recall seeing it on there last year. Could it be some sort of fungus?

I bought it and opened it last year. I stored the mulch in it's
original bag and then placed that bag in a trash bag and tied it up.
I've kept the bag in my spare room since I got it last year.

If the mulch has a fungus, wouldn't it be bad to use on plants such as
tomatoes and peppers? I'm growing tomatoes and peppers in large pots
and was going to use this mulch in the pots. I'm worried about the
fungus infecting these plants.