[Kleftiwallah]

Good afternoon everyone,
the Memsahib wants her raised flower bed raised (it's an age thing) but the top row of bricks are covered in dry algae and lichens.  Do I have to remove all this growth with a wire brush before laying more bricks?
  Cheers,  Tony.

[John]

Send £5 and I'll say no so you can blame me later

[Subversive_plot]

Just tell her "I'm sorry, I though you wanted it razed."

[mumofstig]

Good advice boys  - but I'd say 'just the top the top edge' and put creeping plants round the edge, to hide soften the effect of the remaining algae