When someone mentions a willow tree, the immediate vision for most folks is that of the classic Weeping Willow. The Weeping Willows fall into two groups, those that thrive in the South and those that can handle the chill of the North.
Babylon Weeping Willow (Salix babylonica)
Babylon Weeping Willow is considered the best of the Weeping Willows for the south, not being happy north of zone 6, but can live to 4 with right conditions. It is a short-trunked tree with an open, broad-spreading crown and long, pendulous branches. Babylon Weeping Willows typically grow to between 30 and 50 feet. Their long, drooping branches form a broad canopy that is often half as wide or more, as the tree is tall. The yellow shoots herald the approach of spring, then turn olive-brown by winter. It's bark is dark gray and deeply furrowed. This willow is very adaptable and will thrive in most soil type except for those that are very fast draining and very dry. Likes bright sun. Is scraggly and poorly shaped under too shady conditions. Needs moisture and loves wet conditions.
Golden Weeping Willow (S. alba var. tristis)
For the North, Golden Weeping Willow is one of the hardiest of the willow family surviving well into zone 3. It forms a gracefully rounded crown to about 50 feet in height with a spread just as wide. It has golden bark, a spreading growth habit, and does well in both wet and ordinary garden soils. It is very rapid growing and develops a sturdy, upright, broad crown with long, bright yellow pendulous branches that often touch the ground. This tree is often planted as a lawn tree. The variety Chermesina, the red-stem willow, is planted for its outstanding winter color
Weeping Willows are deciduous. The leaves are long and narrow, most between 2 ½ and 6 inches long and one half inch wide, slightly wider near the base, light green with a finely toothed margin.
All willows have separate sex trees. Their flowers, called catkins, are a light gray-green which become yellow as they ripen. They appear very early in the spring, late February or early March, before leaves emerge. By mid-April they have turned greenish-yellow and formed seeds with tufted hairs. These are released into the wind and are coveted by songbirds, waterfowl and small mammals.