I belong to the Dogwood Garden Club in Coquitlam. Two weeks ago Wim VanderZalm came to our monthly meeting to inform us about how to keep our gardens green. I asked him if it was possible to grow a pecan tree in Vancouver. He replied he had never seen one in Vancouver and imagined there was some reason they would not grow here, bid did not know what it was. Well, will pecan trees grow in Vancouver?
It should grow, as a fairly slow-growing specimen tree, without trouble (it does so rather further north in e.g. southern England). I doubt that it would get enough summer heat to mature any nuts, though.
One at the Seattle arboretum was 86 1/2 ft. high last year (2006), "sets some nuts but none ripen fully" (Jacobson, TREES OF SEATTLE - SECOND EDITION). Another in the same collection was 88 1/2 ft. tall the same year. Jacobson lists a total of 6 specific examples for Seattle, says pecan trees are "very rare" there. Vancouver is even less warm in summer. Walnut trees would be a much better bet, unless one wanted to have a large novelty tree grown primarily for its decorative foliage.