Mold reproductive elements. Mold spores are in the air and on all surfaces except perhaps in a surgical theater or room. Molds need moisture in order to grow. When there is sufficient water or high humidity and condensation on a cooler surface. in order to germinate the spores need sufficient moisture, an organic material (wood, paper, leaves, biological tissues, human or pet food, etc.) and an acceptable temperature in order to grow into a mold mycelium (mass of growing mold).