I must have been lucky and got a lower level spawn, but I managed to take him down after about 20 mins with my 39 Druid and KEI / 224 Wisdom. Not really worth it for the experience, but he dropped a Tree Weave.
It was a pain though, had to keep Ro's on him the whole time, and Root started insta-breaking when he hit about 35% life. After that I just med kited him keeping up just enough mana to keep dots and Ro's on and sitting at the ticks.