Abstract: A plastic sheath for wood bulkheads and the like which includes an elongated plastic sleeve configured and dimensioned to cover at least three sides of a generally rectangular wood board and at least the marginal edge of the remaining side thereof. The sleeve has a front panel covering a front side of the wood board, two side panels each joined to the front panel for covering opposite side edges of the wood board and at least two rear flaps each joined to an opposite one of the opposite side panels for covering at least the marginal edge of a rear side of the wood board. One of the side panels has a generally centrally disposed tongue and the other of the side panels has a generally centrally disposed groove for joining a multiplicity of so-sheathed boards together in a tongue-and-groove manner.