Caroline McChesney, 49, denies being the person responsible for the spate of incidents between June and September last year which began months after her husband David died.
Glasgow Sheriff Court heard Dr John Maclean's cars were damaged with repeated flat tyres, scratches on the paintwork and abusive names scratched onto the bonnet of his car and written on his garage door and garden gate.
He told the jury he was sent cards with messages including "Going on holiday contact you wene (sic) back" and "How are you at putting out house fires".
Dr Maclean, 38, from Hyndland, Glasgow was one of David McChesney's doctors up until he died in October 2012.
The doctor gave evidence at the court at Caroline McChesney's trial - who was also a patient at the Turrett Medical Practice in Kirkintilloch where he is a partner.
She is accused of engaging in a course of conduct which caused Dr Maclean and his wife Rebecca fear or alarm.
Dr Maclean said that after one incident when his tyres were slashed, his car was too badly damaged and had to be scrapped.
His wife's car's tyres were also slashed, her car was scratched, and the Mercedes badge from the front of the car pulled off.
Dr Maclean said the police were informed on each occasion when something happened and on a number of dates he phoned into his surgery where he worked as a GP to say he was unable to come in to work.
Procurator fiscal depute Richard Hannay asked: "What did you think when you saw this card?" The doctor replied: "I was angry, I was frightened, realised that this appeared to be a concerted campaign."
McChesney from Lennoxtown, East Dunbartonshire, denies the charges and the trial before Sheriff Martin Jones QC continues.