Weeping willows are fast growing trees that can be excellent shade trees. Willows are one of the easiest trees to root, because they have a natural plant hormone, indolebutyric acid (IBA), which is found in many rooting compounds, so they are easily rooted in water.
When you have cuttings with established roots, you know it is time to get them into the ground. This is a fairly simple process, as the most difficult part of propagation is already done.
Select a spot to plant your willow cutting. They do well when planted as single trees near a lake or pond. They can also be trained to be used for shade near a patio or deck. Do not plant in an area in which you wish to grow flowers, as their root systems spread rapidly and plants do not grow well beneath them. Willows tolerate most soils, even those that are poorly drained, but they do not do well in acidic soils.
Dig a hole in the soil, deep enough to accommodate the stem of your cutting above the highest root growth and five or six inches in width.
Add compost to fill the hole about halfway. Fill the remaining space with soil that was removed and mix well with the compost.
Make a hole with your spade handle in the composted soil deep enough to cover roots.
Remove rooted cutting from water and place it in the hole, being careful to place roots in a downward direction.
Fill in with soil. Make sure roots are completely covered.
Firm the soil around the cutting, but do not pack it down tightly.
Water thoroughly and mulch with organic materials to retain moisture. Good choices are straw, hay, pine needles, because they won't pack down into an air tight mass. Two to six inches should be enough.
Keep moist until roots become established and new growth is visible. Then water regularly and watch your weeping willow grow into a beautiful tree.