A unique foldable mounting bracket assembly for mounting and securing vertically disposed accessories for decks and patios. The folding mounting bracket assembly when supporting vertically disposed cylindrical post requires both an upper and lower bracket. These brackets are mounted to the vertical post. When these brackets are used in conjunction with the railing of a deck the brackets can be mounted to the vertical railing support post below the top railing horizontal support cross member and above the lower support cross member. This unique foldable mounting bracket when not in use stows flat against the vertical support post not protruding out of the envelope of the standard 2″×4″ railing horizontal members.