Prepare a small pot to root cuttings by filling with equal amounts of perlite, sand and peat. You can also very fine gravel as a rooting medium. Pour about an inch of the rooting hormone into the plastic cup.
Cut 9- to 12-inch sections of softwood cutting using a sharp scissors and measuring from the stem tips. The diameter of the cuttings should be about the size of a pencil.
Remove all leaves from the lower 1 1/2 to 2 inches of the stem. Leave the other foliage as it naturally continues to produce a substance that helps with rooting.
Create planting holes in the rooting medium by inserting a pencil about 2 inches deep. Dip the base of each cutting into the rooting hormone and plant immediately in individual planting holes.
Firm the soil well around the cuttings. Water well.
Place the whole pot in a large clear plastic bag and close the top with a rubber band to help create a greenhouse effect. Place in warm, bright area out of direct sunlight.
Open bag every three to four days and water enough to keep soil moist. The cuttings should root within a few weeks. Check by gently tugging at each cutting. Rooted cuttings will hold their ground.
Let plants get stronger and well-established before transplanting the new willow trees to a permanent spot in the garden.