A weighted support assembly for supporting an upright post. The support assembly comprises: - a base frame comprising: - an elongate base member attached to the post and extending outwards from the post; and - a plurality of upright elongate members ascending from the base member; - a plurality of weights stacked in layers upon the base member; and - a top frame comprising: - an elongate top member attached to the post and extending outwards from the post above the base member; and - a plurality of elongate members descending from the top member. The ascending members engage telescopically with corresponding said descending members, and each said weight defines a hole therethrough which is penetrated by at least one of said ascending or descending members.