Surprisingly, mold will start growing immediately after spores are attached to an item. Mold can easily grow within 24 to 48 hours, and will begin to colonize in 1 to 12 days. Most times, mold is already a problem before it is discovered. Due to the fact, that the spores are hard to destroy, mold will sometimes return even after the mold source is gone. That’s why it is vitally important to contact a mold restoration company for appropriate and permanent remediation.