Green Firewood has a moisture content greater than 50%. Wood that has been cut down within 12 months should be considered green. Green wood is dangerous to burn indoors. It doesn't generate much heat because the fire ends up just evaporating the moisture inside the wood (as steam) – there is more water than wood in each piece. Green wood also smokes badly and leaves creosote deposits inside the chimney, which is a chief cause of chimney fires. Signs of green firewood include: damp on cut ends, tight end grain, uniform wood color, heavy wood, intact bark, mold/fungus, strong smell, sap, bugs or a dull "thud" when pieces are banged together. If you have green wood – don’t burn it. Just find a place to store it properly until next year.