Willow trees are fast-growing and hardy trees. Often homeowners will plant them in low-lying areas to take care of water problems. The willow tree uses a lot of water every day, drying up soggy soils and improving the look of the area. The actual rate of growth is faster than most trees, but it also tends to be short-lived. Of course, like any other plant, there are variables that affect the growth rate of the common weeping willow tree.
Soil type makes a difference when growing willow trees but not greatly. Since the roots of the willow tree are highly invasive to the area, aerated and sandy-type soil will give the roots the easiest base to stretch through. Clay tends to be very hard, especially during the heat of the summer, so it will naturally slow down the rate of growth. Since the tree needs water, the roots will eventually grow through hard soil, including pipes so don't plant willows near plumbing or septic fields.
Water is the life of the willow tree. It will grow 2.4 to 3 m (8 to 10 feet) taller in one season if it has access to plenty of water at the root level. Often you will see willow trees planted near the edges of ponds where they can reach into the underground sources of water. Their roots act as a soil stabiliser at the same time, especially useful along brook banks.
One of the characteristics of wet areas is low pH, so it stands to reason that the willow tree grows best in areas with a low pH range. Willows in damp areas with acid soil will thrive compared to areas with more alkaline soil types.
Sunlight is the most important ingredient in the fast growth of a willow tree. The hundreds of leaves along the constantly stretching branches collect the sun's energy. Through photosynthesis, and the other processes in cell growth, new growth occurs, carbon dioxide is used and oxygen produced. Trees growing in full sunlight in loose soil with a low pH and plenty of water will outgrow just about any plant in your yard until it reaches its mature height of about 12 to 15 m (40 to 50 feet).