The cost of the phytosanitary inspection/certificate is added to the cost of the daylily order so its cost should by itself not affect the willingness of a daylily grower to ship to Canada. Most US growers that are still willing to ship to Canada have a minimum order value. I have always assumed that means that the process of cleaning the daylilies for the phytosanitary inspection, arranging the inspection, the labelling and the shipping procedures make it more fuss than it is worth to most growers.