Willow trees are flowering trees identified by typically elongated branches and leaves. In Assyria, Sumer and Egypt these trees were attributed with healing due to the salicylic acid found within the bark, a raw form of today's aspirin. These trees are commonly cultivated for their attractiveness, and are often seen in cemeteries and along riverbeds.
Willow trees are able to reproduce without any type of fertilization taking place. They are able to create genetic copies of the parent plant when fallen branches take root near water sources. Willow trees are notably adept at vegetative reproduction with the ability to sprout from branches, even upside-down.
Like other flowering plants, willow trees also reproduce through seeds. Willow seeds have long hairs that can be carried long distances by wind or water. They are hardy in moist nutrient-rich soils, but are sensitive to drought. A few days without water greatly decreases the seed's ability to reproduce, according to "The Illustrated Book of Trees: The Comprehensive Field Guide to More Than 450 Trees of Eastern North America," by William Carey Grimm.
Willow trees begin to flower and, following fertilization, produce fruit at around 10 years of age. As the tree ages it is better suited for successful reproduction, primarily between the ages of 25 -75 years. The seeds are usually ripened and spread throughout early April until late July.
Willow trees prefer full sun, warm weather and large amounts of water. They are known to germinate best in muddy riverbanks, streams, lakes and swamps. Seeds are very sensitive to lack of moisture and prefer soils that are able to sustain water for longer periods of time, such as clay soils versus sandy soils. Since willow trees are very adept at reproduction, they are often found among other trees in large groups.
Considerations and Care
Watering willow trees is very important, especially during dry climates. This sensitivity to drought causes many willow trees to produce wide-spreading roots that can clog pipe systems and the support structures of houses. To sustain a healthy tree and to prevent contamination of nearby aquatic life, pruning is important. Decomposing leaves produce many toxic chemicals that can threaten nearby water sources.