In this paper, we propose Greedy Zone Routing, an alternative routing architecture for wireless ad-hoc networks. Greedy Zone Routing partitions the network into zones, which are assigned geographic coordinates. Messages are routed in two levels, where in the zone level greedy geographic routing is performed between zones. Routing within a zone is performed based on the local routing trees. We demonstrate that our protocol outperforms a classical tree based routing scheme, where RPL routing protocol is based upon. We believe that our protocol can be adapted into a tree based protocol like RPL for improved scalability and performance.