Plant as early as possible in the Spring. Repeat plantings around here can be done in early August. We have many great peas we would love to offer but we have 2 big issues with seed production here in Iowa, rabbits and hot weather. We have so much going on in the Spring we frequently miss the narrow window when it goes from winter to summer when they need to be planted to get the best seed. Issue two is rabbits devour most of our plantings as this appears to be one of their favorite plants. In 2018 we went from frozen ground and snow on April 18 to near 90 a week later. UPDATED FOR 2021.