Posted on 20 May 14 at 18:20
Garden Tour is still unlock-able but due to the low frequency of winning a game under these conditions I don't think you'll like it.
Simply (well not so simple): As plants, defend the garden at objectives 2 to last. Basically don't get perfect wins. Although, on the bright side, you're able to switch teams and still have it counted.
*After the recent Zomboss Down DLC, the Zombie Perfect Win bonus was added and in order for Zombies to win, they'd always fulfill the condition of a "Perfect Win" which oddly enough does not count towards the achievement.