Koubachi’s sensor looks something like an inverted golf club. From end to end, it’s about seven inches long. Most of that length comes from the metal pole that actually sticks into the soil, with a moisture sensor at the very bottom. The rest is an egg shaped plastic housing, which holds the batteries—two AA, included, and rated to last for more than a year—more sensors, the wireless transmitter, and a single button. It’s…
