Petunias are often a gardener's staple. They bloom in the spring, usually without fail, and can survive and thrive with little care. There is no need to fork out money for seeds to propagate petunias. Take cuttings from existing petunia plants and encourage them to grow roots. Eventually they will become their own individual plants. Petunias are easy to root, especially in the spring when the plants are rapidly growing.
Choose a healthy looking stem from a healthy petunia to root. Cut off 3 to 5 inches of the stem just below a node (where leaves grow). Make a clean cut uing a pair of sharp clippers or scissors.
Pinch off the petunia leaves on the bottom 1-½ inches of the stem. Do not plant the leaves.
Dip the cut on the bottom of the stem in rooting hormone to help encourage the roots to form. Shake the excess rooting hormone off of the stem.
Plant the bottom 1-½ inches of the stem in a container with drainage holes. Fill the container with equal amounts of sand, perlite or vermiculite with peat moss or sphagnum moss. Water the rooting medium (soil) until it is slightly moist.
Cover the cutting with plastic or glass if possible to keep the cutting from losing too much moisture.
Set the cutting out of direct sunlight in an area that is around 60 to 65 degrees F. Keep the soil moist and check on it every two to three days.
Tug gently on the cutting to check if it has rooted. Resistance from the cutting indicates that roots have formed. Transplant the cutting to a larger container in six to eight weeks.