Port Hills farmer Tom Magill could only watch in despair as seven years of hard graft went up in smoke.

Half of the 240 hectares of tussock farm land he leased with partner Stella Bauer was scorched in Christchurch's Port Hills blaze as a "wall of flame" raced down the valley towards him last Wednesday night.

"We were camped out in a paddock on Cashmere Road and all we could see was flames. The firefighters weren't interested in us - they were too busy trying to save homes. At one point (worker) Durk (Kingma) and I put out the flames that threatened the woolshed with our oilskin vests," he said.

Magill and Bauer leased 1650ha of farmland in five blocks spread across the Port Hills between Governors Bay and Cashmere Road.

No stock perished in the fire and nor were farm buildings lost on the lease blocks, but the loss of grazing land and fences has set them back.

On Monday last week, the young couple were aware of the fires burning on the hills and although they weren't that concerned, moved stock to lower levels as a precaution.

"At that point, we were more worried about the stock over on our blocks in Governors Bay," Magill said.

"We kept an eye on the flames as they came over the hill and down towards Lyttelton Harbour."

On Tuesday they could see smoke coming "over the hill," towards their land on Cashmere Road but still weren't that worried.

On Wednesday the shift in the wind direction turned flames towards Cashmere Road, and Magill realised they were in trouble.

"We moved 800 breeding ewes and 200 lambs across to the other side of Cashmere Road. Then all we could do was watch," he said.

By morning, 150ha of prime late summer grazing was gone.

"By Thursday the fire had settled and it was a matter of getting our heads around what had happened," Magill said

Although the area was cordoned off, on Friday he and Kingma went "up the hill to have a look".

"It was devastating," Magill said.

"We have been building up this farm for seven years, and have done all the fencing ourselves. An initial estimate I'd say is we've lost six kilometres of fenceline. Even some of the fencing that looks like it's come through the fire okay, will apparently rust out if it isn't replaced.

"About 150ha of tussock country was burnt. Our late summer grazing and shearing and winter shelter are gone.

"How long does this land take to grow back? We haven't a clue. We are looking for replacement grazing."

Magill had nothing but praise for the support he had received from the Banks Peninsula Farmers Group, the North Canterbury Rural Support Trust, and Federated Farmers.

"We needed lambs moving off the property on Friday, and Rex Gebbie of Banks Peninsula Transport organised it for us in 24 hours," he said.

"The amount of help offered to muster stock, clean up the property and offers for grazing where they are giving away their surplus/back-up feed,all this help offered is very overwhelming. Just to know people want to help makes the whole event a lot easier for us," Magill said.

Magill said the insurance was "being looked into."

"We are hoping the fencing is covered," he said. "We are just crossing our fingers at this stage."

- PNC Sources/Stuff