I have a similar setup but it also has an esp8266 hooked up that sends data to thingspeak. It then communicates with Pushbullet that notifies me to water the plants.
I had it hooked up to internet with an ethernet shield so that it tweeted when the water level was low. That proved to be not very practical, as network cables are pretty rigid and ugly, and the plant had to be in the vincinity of a network socket. At that time, I couldn't be bothered anymore and I made something else.