An interactive irrigation system exchanges information between an irrigation controller and a distal computer, between the irrigation controller and a user, between the user and the distal computer, and between the distal computer and a third party. The information is preferably exchanged over an Internet communication system. The exchanged information includes the following: irrigation scheduling; quantity of water applied to the landscape at the user location, which is compared to ETo values; warnings to users when potential problems with their irrigation systems are detected; and other irrigation information that is useful to the user or a third party.