Here is another WiFi enabled system that makes watering your plants more convenient. The netAQUA 9D irrigation controller uses an Internet weather service in addition to local sensors to get the job done more effectively. You get WiFi and Ethernet connectivity options. This supports up to 45 zones.
The device has a weatherproof enclosure. You will be able to connect to it form your smartphone, tablet, or computer. Costs under $270 at this time.