Mern IX. The last of house Gardener.
Would also like to add the comment that I'm least happy with GRRM's choice of names when those names correlate too perfectly with the position or temperament of the character. For example House Gardener (ruled the most fertile part of Westeros), House Florent (another agricultural-based name in the reach), House Redwyne (they make red wine), House Stark (because they are all... well stark and spartan and such). Also see Mance Rayder (because he like... raids... south of the wall), etc..