These “side” issues include such matters as resolving substandard access to the public road and meeting bulk zoning regulations such as lot width and area. A Boundary Line Adjustment, then, is an Administrative action by the city or county planning authority. In contrast, a Boundary Line Agreement is a judicial action.
Adverse possession allows someone to claim ownership of land if they have occupied it for a specific period without the legal owner's permission. In the context of garden boundaries, if a neighbour has used or maintained a piece of land for seven years or more, they may have a claim to that land.
The Boundary Line Agreement (BL AGR) provides a procedure for County review whenever a point or line determining the boundary between two or more parcels of real property cannot be identified from the existing public record, monuments, and landmarks or is in dispute. RCW 58.04.
You and your neighbour can create a 'boundary agreement' to record: the boundary between 2 properties. who's responsible for maintaining a hedge, wall, tree or fence between 2 properties.
A boundary line agreement is a legally binding document that sets clear boundaries between neighboring properties, providing certainty and preventing conflicts.