Crop monitoring systems are one of the important aspects of Smart Agriculture. Due to explosive growth of population there is an increase in demand for food products while urbanization is causing shortage in manual labor. As the yield of a crop is greatly affected by many climatic and environmental parameters, there is an urgent need for efficient crop monitoring. Rapidly advancing IoT (Internet of Things) technologies have shown very promising results and have automated most of the traditional processes in farming. An efficient Crop Monitoring System (CMS) is proposed which automates the monitoring by using the IoT and real-time data is shared securely using private IOTA Tangle Distributed Ledger Technology. The proposed application equips farmers with required information which will help them make decisions promptly based on the real-time environmental parameters of the crop and reduces human labor. Data privacy and security are other important aspects addressed in the proposed system by setting up a private IOTA Tangle. Unlike public distributed ledgers, private distributed ledgers provide data privacy and security by allowing only known participants to join the network, thereby limiting the adversaries trying to tamper with the data. Practical implementation of the proposed system is done and analyzed for scalability and reliability.