"Salix nigra" is dioecious, which means it has separate male and female trees. Flowering may be climate dependent. It flowers during February in the southern part of its range, and flowers until June in the northern parts. These trees are capable of producing seeds when they are around the age of 10 years. The black willow continuously has good seed crops year after year, with only a few failures. The seeds require very specific conditions to germinate. They prefer soil that is very wet or flooded. After they germinate, they can experience excellent growth if they are exposed to high sunlight and copious moisture during the growing season.