MPI sent six large wool bags with double liners and instructed Sayers to seal the waste in the bags and leave them on her front lawn for collection.
Not wanting to be responsible for spreading the spores, she also offered to carefully cut down and bag three of the infected plants.
MPI agreed, so on May 30, with a friend's help, she did just that. The only infected tree she left was a pohutukawa which, at 8m high, was too large to remove.
She then had five wool bale-sized bags of garden waste on her front lawn waiting to be picked up.
On June 8, however, she received another letter from MPI telling her the bags would no longer be collected.
Eliminating the fungus was no longer feasible in Kerikeri so MPI would not remove infected plants from her property. Nor did she have to remove the plants herself - but by then it was too late.
''I'm cheesed off they changed the rules mid-stream. I was just trying to be helpful,'' she said.
''If I'd known they weren't going to take the bags away I wouldn't have cut out my ornamental plants and I wouldn't have created an eyesore on my street.''
The June 8 letter gave her a number of options for disposing of the infected material. Two were too costly for a pensioner — hiring a contractor or taking the triple-sealed bags to a transfer station — and her garden wasn't big enough to bury the bags.
Sayers said she knew of three other Kerikeri residents in the same position, though none had as many bags awaiting collection as she did.
Lloyd Parris, who also lives in Kerikeri, said he had a similar experience after biosecurity workers turned up at his property and put red tape around two small plants.
"They were dressed in space suits so you'd think this was really nasty stuff," he said.
As they left they said someone would be touch within days. However it was only weeks later, after he chased up MPI, that he received any instructions.
In the meantime he had pulled up the plants and sealed them in black bin bags. The plants cannot be taken to a green waste facility so he is planning to burn them.
"There was no urgency. It just seemed so strange," he said.
MPI did not respond to the Advocate's enquiries by edition time yesterday after being asked for comment on Monday.
However, in April, after 11 months of trying to eradicate myrtle rust, the ministry signalled it would instead try to manage the disease over the long term.
That came after the number of infected sites passed 540 and the disease was found in the South Island for the first time.
Efforts would instead focus on researching treatments, resistance and susceptibility, and improved seed banking.
MPI is, however, still asking people to report any possible cases to its biosecurity hotline, 0800 80 99 66.