After starting farming on his own account in 1981, following in the footsteps of his father and grandfather, there was a "massive" storm which killed 1000 lambs.
There was snow for 10 days on the South Otago property, which had been in his family since 1919.
There were already some trees on the farm but he stepped up planting for shelter belts, which also doubled as shade cover for stock.
Since then, the plantings have been expanded for environmental and beautification purposes and now cover more than 50ha.
The result is an award-winning property, which will be on display to the public during the New Zealand Farm Forestry Association's 56th annual conference in Otago from April 11-15.
Up to 200 people are expected to attend the conference, which a 15-strong committee has been planning for about two years.
Mr Roulston has a mixed-farming operation on his 400ha rolling property, with sheep, beef, including a Charolais cattle stud, cropping and an outdoor piggery.
The creek that ran through the property has been fenced off and planted out and freshwater crayfish are now reappearing.
Plantings had also been done to encourage birds, bees and seasonal colour.
Two years ago, a storm in the South at lambing time claimed a million lambs on Otago and Southland farms.
At Chardale Farm, Mr Roulston moved lambing ewes into blocks of trees "everywhere" and still managed to achieve 140% lambing.
When it came to planting, he worked with a forestry consultant and they discussed various trees and options. Another professional does the planting.
One of his highlights was winning the 2008 Transpower Landcare Trust Grants Award for innovation in sustainable farm forestry.
While "bank managers don't like trees because they can't see a return", they did not work on the property and so did not see the benefits which, along with shelter, included grass growth and stock health, Mr Roulston said.
Mr Roulston is looking forward to the conference, which is being hosted by members of the South Otago and Mid Otago Farm Forestry Associations.
It was good to show people what could be done on a property and there was an interesting programme that should appeal to a lot of different people, he said.
With trips to Mahinerangi and various properties throughout South Otago, including Neil and Pam Cullen's farm, in the Glenomaru Valley - Mr and Mrs Cullen won the association's Husqvarna South Island farm forester of the year award - there was the opportunity for a "good look" around the region.
People can still register for the event and they can choose which days they attend.
"It's not often you get a conference and field days of this nature and calibre around here, and there will be some interesting speakers," Mr Roulston said.
It was a good promotion for the area and for Telford, at which the conference will be based.
Mr Roulston has been heavily involved with Telford through the years and described it as a "great asset" to South Otago and New Zealand.
Mr Roulston, who has a long-time interest in cooking, is in charge of catering for the event.
At one stage, he combined farming with a part-time chef's course at Otago Polytechnic and he caters for private functions, including weddings.
During the visit to his farm, he will serve spit-roasted home-grown pork for lunch.
The South Otago branch of the New Zealand Farm Forestry Association was one of the strongest in New Zealand, he said, which he attributed to the likes of Vic Stephens, Ken Stephens and Ken Jones.
They put in " a lot of work and their enthusiasm for forestry rubbed off on to others.
He was quick to point out farm forestry was "not just about planting pine trees or macrocarpas" but covered a lot of different aspects.
Mr Roulston has planted many varieties - everything from fruit trees, flowering cherries and scented poplars, to oaks and bay trees.
Planting extensively was not difficult; it just required "a bit of vision" and it did not have to be done in one year, he said.
"If you do a creek a year, you make a difference over 10 years."