Weeping willow trees are some of the easiest trees to root. They require little more that some soil and water to grow along with a clipping of the tree. The main thing you have to be careful about when rooting or planting a weeping willow is placement. The roots of the tree seek out and drink a lot of water, so it is best to plant them near a water source such as a pond or stream. Do not plant a weeping willow near a septic system as the roots could damage the tank.
Cut or break a branch off of a weeping willow tree. Make sure that it is fairly new growth. Use pruning shears for a clean cut and clip at an angle if possible.
Place the cut end of the branch in a pot of soil or in the ground. The depth of the hole will depend on the length of the cutting. For example, if the cutting is 18 inches long, place the branch in a hole that's 5 or 6 inches deep so the branch can stand up on its own.
Give the branch some water to moisten the soil around the cutting so it is damp, but not soggy. Check the soil daily to see if it needs more water. The willow tree drinks a lot.
Check the soil and water as needed until you see growth. Once the tree is established, water if there is a drought--otherwise, the roots will spread and seek out water on their own.