A support system and method for securing vertical centered placement of various nominally sized wooden posts within a cylindrical form within the soil or within a cylindrical hole alone comprises a plurality of spaced apart adjustable post support braces formed from a plurality of radial support braces. The radial support braces each have a first component that has a body section configured for attaching the first component to a wooden post. Each radial support brace has a second component that has a first section configured for supporting the second end of the first section in abutment against a peripheral inner wall of the form or hole and configured to cooperate with the second end of the first component to permit longitudinal movement of the first and second components. Each radial support brace is further configured to lock the first component in position relative to the second component.