You should talk to the owner first; then if that doesn't work report it to #311. Problem is the city receives the complaint, sends them a letter and closes the complaint immediately. Hence, nothing is ever done by the city--Good luck I have one too!!
Report it, I think.
Definitely report it, and it is best that you take a photo and attach that.
If you are not a neighbor to the owner, it is difficult to just go up to his door and talk to him about the piles of trash in his yard. Perhaps you are not aware that we live in a City that has a comprehensive zoning ordnance, which applies to all houses and such within the City limits. Issues such as piles of trash, refuse, garbage, etc. on property are not allowed by City Ordinance. Offenders who refuse to comply can be taken to Court and convicted. The MINIMUM fine is $150. The City does NOT "send them a letter and close the complaint immediately". The issues here at this online 311 report site are marked "closed" by the City when they have acknowledged them and are taking care of them through their channels. The problem is that this takes time.