To maintain a lush border, a good watering system is required.  This can be  either by drip irrigation (leaky pipe) or by a garden watering kit (which normally comprises of a pipe system and several micro sprinklers) www.rainbird.SXB-360SPKY.

This type of system can normally be self-installed but depending on the size of your garden perhaps a detailed drawing, mapping relevant areas, water flow and amount of border to be watered from end to end needs to be considered to ensure maximum benefit. 

Irrigation Services UK Ltd would be happy to help in these circumstances.