The shipping season for the bare-root plant material is during the dormant season when the plant is not in active growth. For many of the spring wildflowers this period begins in May as the plants set seed and lose their foliage .Some plants will put out leaves again in fall but for most their growing season ends in late spring and they don't have foliage again until the following spring.
From this time on the plants can safely be stored, transplanted and shipped without any stress on the plant The heat of summer should be avoided but fall through late winter into early spring are good times .
Although we have cold winters here in the Missouri Ozarks, spring comes early here .I like to have the spring orders shipped by early to mid March. I realize that many of you northern gardeners may not be wanting to receive plant material that early. Please communicate with me about your desired ship date and I will try and work with you.