I recently installed seventeen plants at a health club in Guildford. The club had a problem with customers parking on the pavement right outside, so rather than having a line of ugly bollards, we put a line of six simple blue square pots planted with Chamaerops palms (my favourite outdoor palm) across the kerb..... and bolted them to the ground!
As I worked, the occasional customer arrived and gave me a very dirty look as I permanently cordoned off 'their' space - job done! Got a similar parking problem? Drop me a line!