The stores targeted were in the George St blocks between Hanover and Union Sts.
Letters were scratched into the glass, meaning many of the windows would have to be replaced.
Mainstreet Hair Design owner Steve Black said he did not notice the graffiti when he came into his store.
The large graffiti scrawl which had been scratched into his window was pointed out by a neighbour.
He replaced the window last year at a cost of $920 and expected it would have to be replaced again.
He has owned the salon for nine years and, in that time, the window had been broken three times.
Mr Black said it "goes with the territory" of having a store on the main street of a city.
Joseph Jones floral designer Rebecca Cameron said the large window which had been scratched would likely have to be replaced.
Police are investigating.
