Yamhill Wheat Grain Seeds. Soft White Winter Wheat. Heirloom. Non GMO. High Germination. Triticum aestivum. Yamhill winter wheat seeds were developed in Oregon in 1969 as a beardless, standard height, cold tolerant winter variety. Yamhill wheat seed is adapted to the winter wheat growing areas of western Oregon, Northern California, and Washington and has been bred to tolerate wet soils better than other wheat crops. Approximately 8,000 seeds per pound.