Taking cuttings from petunias requires garden shears, paper towels, rooting hormone, a pencil, a container, sand, perlite, peat moss and a plastic bag. Roots should appear in two to three weeks.
Prepare the container
Fill the container with equal parts sand, perlite and peat moss. Mist the mixture with water until it is completely moistened. Poke holes in the mixture approximately 2 inches apart using the pencil.
Cut off the stems
Choosing young, healthy stems, make a cut 6 inches from the tip, just below a leaf node. Remove the leaves from the bottom 1 1/2 inches of the stem. Cut off any flowers on the stem. Wrap the stem with a moistened paper towel.
Apply rooting hormone
Remove the paper towel, and place the cut end in the rooting hormone. Tap the end to shake off any excess.
Plant and cover with plastic
Place one powdered stem in each of the holes poked in the soil. Gently press soil around the cutting, stabilizing the stem. Drape the plastic bag over the cuttings to prevent moisture loss. Place the container in a cool dark place. After three weeks, gently tug on the cuttings. If you feel resistance, this is a sign roots have begun to grow.