Painting Texture Question..Need Help

i am fair new to blender but am working on a scene and want to paint the floor (grass texture)

so it looks like dirt as it meets the path but when i do it tiles like this?

i am using cycles render and would appreciate any help . ty

What do the UVs for the floor mesh look like ?
What do the material nodes look like
Are you painting directly onto the floor grass texture or another texture to control texture blending ?
Where is your .blend file to review (pack all textures into blend file before saving)