Making it into the top 3, and my personal favorite firewood is black locust. Black Locust burns around 28.1 million BTUs per cord. Considering white oak burns around 26.5 Million BTUs, Black Locust is definitely HOT! Black Locust is also like a weed, it grows back quick and is very prominent on the east coast.
Black Locust is a easy tree to identify. If it is cut down the wood is a yellow, almost goldish color, with a brownish heartwood. It could be confused with another member of the top 5 list, Osage Orange, but we will cover that when we are there. The bark tends to be deep, but also tight to the wood and grayish/brownish in color. The leaves are alternatively arranged and in the spring have a white bloom that are very pretty. Did you know that Black Locust is more rot-resistant than pressure treated lumber? This makes it an excellent choice for not only firewood but also many types of fence post, and other wood products that are outside.