New wood restrictions affect six Penn. counties

(Aug. 6, 2012) -- With these new finds, 28 counties are now dealing with the invasive ash tree-killing pest. Due to the difficulty in distinguishing between species of hardwood firewood, all hardwood firewood and wood chips—including ash, oak, maple and hickory—are considered quarantined. No firewood may be moved into Pennsylvania from another state without proper inspection and certification.