Complex event processing systems have gained importance since recent developments in communication and integrated circuits technologies. Developers can easily develop many smart space systems by connecting various sensors to an Arduino as an internet of thing device. These systems are useful for many places such as factories, greenhouses (plant house) and smart-homes. Especially in plant houses when the desired humidity, temperature, light and soil moisture drops the certain level, the users should be notified through their smartphones. The sensor information is sent to a central server over the internet via an access point. The collected sensor data needs to be processed online to check whether an event is occurred or not. The event processing system based on a complex event processing tool is created on the central server. It is also an important issue to inform mobile users whenever an event occurs. A publish-subscribe event based system is implemented on the central server. A mobile user is subscribed to the desired event topic. When an event occurred, which is related with a specific topic, an alarm notification is sent to the mobile users about the event information so as to take necessary precautions.