Fertile Earth WS-1 WaterStik Plant Moisture Sensorm, Indoor By using the WaterStik InstaRead button the user can simply push the button and know immediately the status of the plant The only device that identifies whether the plant has been over watered Color of light indicates if the plant needs water or not Blue means overwatered, green means good, yellow means water soon, and red means water now. Depth gauge allows you to adapt the WaterStik to different plant types and watering habits