Multi-channel based routing approach may utilize more than one channel for communication and has the ability to provide high performance by more rigorously countering interference, collisions and re-transmissions than the single-channel routing methodology. This research work aims to establish guidelines for future research and development in the area of Wireless Sensor Networks (WSNs) based on the critical analysis of the prevalent multi-channel based routing protocols for WSNs. Due to extensive ongoing research in this domain, a significant number of multi-channel routing strategies have been presented which need to be discussed. To explore, this work not only reviews a variety of single/multi-path and single/multi-radio multichannel routing protocols for WSNs under a novel taxonomy, but also outlines their relevant pros and cons. In order to help design new multi-channel routing strategies for WSNs, an insightful review on the applications, current design issues and associated challenges of multichannel routing in WSNs are in-depth scrutinized. Towards the end, some prospect trends are put forth regarding multi-channel routing for WSNs which may provide a road map for future investigation.