Why do I always get weeds along edges such as sidewalks, driveways and streets?

The pre-emergent barrier applied to your lawn in early spring is typically broken due to weed eaters and edgers. Also weeds need sunlight to germinate and again weed eaters and edgers expose bare dirt allowing weeds to grow. In addition, concrete tends to heat the soil along edges to warmer temperatures, compared to the rest of the lawn, which is ideal conditions for certain weeds to germinate and begin growing.