The Cyber Omelette: Automated Plant Watering with a Raspberry Pi
Tutorial - Using Capacitive Soil Moisture Sensors on the Raspberry Pi - SwitchDoc Labs Blog
Amazon.com: ACEIRMC 2set Soil Moisture Sensor, Icstation Humidity Detector, with Corrosion Resistant Probe, Digital Analog Signal Output for Arduino Raspberry Pi Garden Automatic Watering System : Patio, Lawn & Garden