Existing coflow scheduling frameworks effectively shorten communication time and completion time of cluster applications. However, existing frameworks only consider available bandwidth on hosts and overlook congestion in the network when making scheduling decisions. Through extensive simulations using the realistic workload probability distribution from Facebook, we observe the performance degradation of the state-of-the-art coflow scheduling framework, Varys, in the cloud environment on a shared data center network (DCN) because of the lack of network congestion information. We propose Coflourish, the first coflow scheduling framework that exploits the congestion feedback assistances from the software-defined-networking(SDN)-enabled switches in the networks for available bandwidth estimation. Our simulation results demonstrate that Coflourish outperforms Varys by up to 75.5% in terms of average coflow completion time under various workload conditions. The proposed work also reveals the potentials of integration with traffic engineering mechanisms in lower levels for further performance optimization.