dr113j from Instructables has decided that the commercial garden watering controller didn’t give him enough flexibility to select time and operation modes, so he decided to build one. As a base, he has chosen an Arduino along with his made Ethernet controller.
What the controller has to do is to drive 12V watering solenoids. So simple transistor circuit is enough on the power side of the board. There is also a DS1302 RTC chip used to track time. The rest is left for software where limits are your own imagination what, how and when you want to water your garden. And of course, it is more fun when you can do this via the web interface. For garden maintenance and cleaning, milwaukee leaf blower can be a great choice, though.