Willows are, "a large family of trees and shrubs that grow along streams and in other moist places," according to the Wisconsin Department of Natural Resources. There are several different types of trees within the willow tree family, including the well-known weeping willow. Willow trees reproduce by means of vegetative reproduction; this is essentially a way in which plants can clone themselves, according to the Missouri Department of Conservation. They can also reproduce by seed.
Like other trees, one of the ways in which willow trees reproduce is by seed. Long, silky hairs on willow seeds carry them quite a distance as they fall; they can also be spread by water, as most willow trees grow near a water source, according to the U.S. Forest Service. Moist soil with good mineral content is best for willow tree seeds, and a period of even a few days of dry weather can greatly and adversely affect the ability of seeds to germinate and reproduce.
Willow trees also can reproduce through vegetative reproduction, when, "root stocks of very young black willow trees sprout prolifically," according to the U.S. Forest Service. Vegetative reproduction does not require any type of fertilization to take place, allowing willow trees an additional benefit in the area of reproduction.
The Missouri Department of Conservation calls the willow tree, "our champion cloner," noting that vegetative reproduction creates genetic copies of the parent plant. The brittle branches of willow trees snap off easily and are frequently carried away by nearby water sources. These branches eventually take root and sprout in new areas. Willow trees are especially adept at this procedure and can even sprout from branches that are planted upside down.
Willow trees grow best along the muddy banks of rivers, streams, lakes, swamps and even drainage ditches. They prefer full sun and warm weather. Seeds are even more in need of moisture, suffering if without water for even a few days. Willow trees prefer clay soil, but can grow well in a variety of soils, many in which other hardwoods are unable to sustain themselves. Willow trees often grow near each other or in clumps within an area.
Growing Willow Trees
It is easy to grow a willow tree. Any cutting placed in the soil in a sunny location and given appropriate care will grow well. According to the Missouri Department of Conservation, there is an old folk story regarding a grandfather who stuck his cane in the ground, which then sprouted into a willow tree. Some theorize that the story may even be true, if the cane was made of willow. However, those wanting to plant a willow tree should consider that, also due to its ease of reproduction, it is difficult to keep willow trees under control on a landscaped property. Pulling small seedlings by hand or using an herbicide will likely be necessary.
Time for Reproduction
Willow trees start producing seeds around the age of 10 years, according to the Missouri Department of Conservation. The optimal time for reproduction is anywhere from 25 to 75 years of age, depending on the tree. Seeds typically ripen and fall from April through July, according to the U.S. Forest Service.