This paper implement Wireless Sensor Networks (WSNs) in agriculture, especially for hydroponics plants. In agriculture with hydroponic method, water becomes the main nutrient for plants. Water and surroundings are become the important factors for plant growth. WSN is used to remotely monitor the quality of water in hydroponic plants. Zigbee is one of wireless technology usually used in WSN since it is suitable for low data rate, low costs, and low power consumption, while a widely used wireless gateway is using WiFi based. This proposed design combines Zigbee and WiFi technology in WSN system. Zigbee based transceiver is used in the sensor nodes side and the WiFi based gateway is used in the coordinator side. The experiment is conducted to test the WSN performance in the presence of Zigbee and WiFi, includes testing the Received Signal Strength Indicator (RSSI), Packet loss and error, and Throughput. The results show that the RSSI value and throughput in network with the interconnected Zigbee - WiFi are decreased about −10 dBm and 0.13 kbps respectively compared to the not-interconnected Zigbee - WiFi. The farther the distance between nodes the throughput is decreased.