Always under-watering or over-watering your plants? Wire up this Arduino-based sensor and save them.

Use cases: Once you're using smart sprinklers and hose valves, you can use a soil sensor as a trigger to determine when or whether to water.

But of course, in practice there is a bit more to it than that. [rbaron] explains exactly how capacitive soil moisture sensors work simply, clearly, and concisely.

Ever wanted to measure soil moisture? Common “soil moisture meter module arduino raspberry compatible free shipping” PCBs might deceive you with their ascetic looks.

Soil moisture is measured 3-6cm around the sensor, so they can monitor larger volumes of soil and, when installed correctly, offer more representative results than other types of sensors.