Robin Thomson visited the council office to complain about another issue but found the premises closed.
However, he noticed the front of the town hall was unkempt with weeds growing within the curtilage, along the edge of the building and between the paving slabs.
So he went home for some weedkiller and doused the offending plants.
He said: “It is some advert for Annan when the town hall looks like that.
“I’m an 83-year-old, nearly 84, pensioner and I sprayed the weeds for them.”