The Blue Jays moved into Rogers Centre back in June 1989 (when it was known as the SkyDome), and since then they've played on artificial turf. They've gone from AstroTurf to FieldTurf to Grass3D as technology improved during that time.
At the team's State of the Franchise event on Wednesday night, Blue Jays president Paul Beeston said the club hopes to replace the artificial surface with natural grass within the next four years:
Beeston: "We know that we can put real grass at Rogers Centre. Our goal is for the 2018 season."— Blue Jays-Official (@BlueJays) January 29, 2014
Rogers Centre has a retractable roof, so sunlight won't be a problem. Cold temperatures early and late in the season might be, but that issue isn't unique to Toronto. Natural grass is definitely doable even though it likely means fewer (no?) non-baseball events during the summer.
Hopefully the Blue Jays can pull the change off and soon. Baseball on an artificial surface just can't compare to grass.