I'd talk to the HOA right away and let them handle it. I don't recommend talking to your neighbor about it, since it would cause tension and misunderstandings, and you don't want that in the long run. The HOA will and is supposed to resolve this for you.

If there is an HOA in the neighborhood, they might be the determining factor of property lines, landscaping guidelines and the like. Contact the HOA.

However, something you should keep in mind is that it is the purchaser's responsibility prior to closing to have a property appraiser come to the land and survey the exact property lines (the county has records). If you failed to do this, any disputes will need to be taken to court.

Hi everyone. We just closed on our first house. We did not know that we have 3.5 feet wide land that along the house until we signed our paper work. After sigining, we come to look at our new house and there is a sign the fence has been take off between our house and other neighbors' house. I noticed that every house in that neighborhood has two side of yard except our...In our property map, it shows we have land on 2 side of the house, but reality only one side yard. What we have to do now.? Talk to HOA or come to tell our new neighbor that is our land.... Please give me some advice..