"We have been tending the strips in front of our place, and doing our neighbour's as well because it is too much for her, and we put the weeds in rubbish bags," said Mrs Tunbridge.
Residents in Terrace St received hand-delivered letters from WDC and contractor Downer this week informing them that they would be "undertaking some remedial works on the newly constructed berm".
The letter went on to say that the work would be carried out at a time when "when the climatic conditions are more favourable to successful growth".
A contact number for Downer was at the bottom of the letter and Mrs Tunbridge said she spoke to an employee there who informed her that the soil used in the berms was sterilised.
"If it was, I wonder where all the thistles came from because they weren't here before," said Mrs Tunbridge.
She said there were a number of elderly residents in the street who were concerned they would be expected to control the weeds until re-planting was done.
Whanganui District Council staff did not respond to requests for information last week.