When are maples usually tapped ?
Red maple is a medium quality firewood , possessing lower heat energy , nominally 5.4 MJ / m³ ( 18.7 million BTU ( mbtu ) per cord ) , than other hardwoods such as Ash : 7 MJ / m³ ( 24 mbtu / cord ) , Oak : 7 MJ / m³ ( 24 mbtu / cord ) , or Birch : 5.8 MJ / m³ ( 20 mbtu / cord ) .