He agrees that it was hard to think about retiring, but now he will have uninterrupted joy "getting the garden under control" with his wife, Meg.
Dr Hartfield said he was meant to be a GP in rural Sussex in England but chose instead to work in Nigeria where he said "you do everything".
"My eyes were opened to the horror of disease in the Third World."
He also trained in tropical medicine for those in poverty in Nigeria. It was hard work and exhausting and the family only returned to England when Dr Hartfield had leave.
But it was satisfying work at the research hospital where he worked, and it was a good time to be in Nigeria as it had just become independent.
The Hartfields had two children at the time - one born in England and the other in Nigeria, and it was now time for them to go to school.
The family did not want to return to England, or go to South Africa, and Canada was too cold. As it happened, a young Salvation Army couple from New Zealand, who he described as "charming", came to stay for the birth of their baby.
They made such an impression on the couple that the young doctor looked in the British Medical Journal for openings in this part of the world. The family arrived in New Zealand from Nigeria in June 1973 and went to live in Te Kuiti.
"New Zealand was a perfect place to come to."
They were, however, wanting a small town by the sea, a good place for gardeners and a lot of music and arts. The Hartfields looked south and found Wanganui. In 1977 Dr Hartfield was invited by obstetrician gynaecologist, the late John Baeyertz, to work with him.
The two specialists never had an argument and never signed a piece of paper to formalise the time they worked together. Theirs was a relationship based on a "gentleman's agreement" which was the mark of two exceptional doctors who dedicated their professions to their patients in the 20 years they worked together.
Between the two, they delivered 1200 babies a year.
Dr Hartfield says he was more a public hospital doctor than a private doctor, but Wanganui Hospital at the time did not want a gynaecologist, but it did need an anaesthetist.
He took the job. However, Dr Hartfield muses quietly, his patients were all asleep, so he worked an afternoon a week with Mr Baeyertz, and after another four years he dropped the anaesthesia.
In 1972, before his arrival in Wanganui, Dr Hartfield read an article in the Annals of Internal Medicine about dying. It alerted him to some of the challenges faced by patients and their doctors.
He was already interested in the philosophy of a hospice. "I used to have student nurses and I saw how difficult it was for them when someone asked: 'Am I dying?' No one ever told them in those days."
Dr Hartfield recalls in 1976 the local Nurses Christian Fellowship asked him to speak at one of its regular meetings.
In the discussion time, student nurses expressed the difficulties they faced when dying patients, who had not been told their true situation, asked them what was really happening. Often this was during bed making or some other routine performed by students only. Much of the evenings discussion centred on the question - should patients be told the truth?
Eventually patients were told they had a finite time to live, there should be unlimited visiting, and painkillers were given as required, not every four hours.
Later, the late Tom Joll was setting up Hospice in Wanganui and Dr Hartfield had now retired from obstetrics and gynaecology. He called Mr Joll to join the hospice bereavement group and Mr Joll asked him if he would like to use his medical experience.
Dr Hartfield agreed and in 1997 he became a medical officer at Hospice, then on Anzac Parade.
Dr Hartfield's anaesthetic background was useful to this type of care, but palliative care was different to other medical fields. "I did not know if I could do it but I found I could. In my generation you could cure anything."
He talked about the mystery of death, and that there could only be an "estimation" of time before those with a terminal illness reach the "cloud of witnesses".
Dr Hartfield, the priest, says this comes from his Christian background and spoken by those who have had a near-death experience where they were met by "those who are awaiting resurrection".
Meg Hartfield has worked at Hospice as a volunteer in day care since 1999, and started the biography service for anyone who wanted to write their life story. After one woman had written hers, the Hartfields took it with them to the UK and gave it to her friend who was in a photograph in the book.
Every year Mrs Hartfield sends out bereavement cards, which she makes, to the families.
And at the door of each of the five patients' rooms is a picture of a bird which Mrs Hartfield has painted - tui, kiwi, dove, plover and goldfinch.
Mrs Hartfield also queried the Hospice logo of the concept of a dove flying from the light into darkness, suggesting that it might be more appropriate for the dove to be flying out of darkness into light. She redesigned the bird which today continues to fly into the light.
Dr Hartfield's reregistration comes up today, but this is one doctor who won't be registering. He says he has been fortunate to do what he liked doing and be paid for it.
Hospice, Dr Hartfield says, is a wonderful place of healing for a lot of people.
"It is run as a family. It can be very sad, but it is a surprisingly happy place."