Begonias are tropical plants that bloom in the spring and last throughout the summer and fall. They are low-growing plants that produce vibrant-colored flower clusters in red, pink and purple. They are annual plants that do not tolerate cold weather and will die back at the first frost. Propagation of begonias can be accomplished by cutting a stem from an existing plant and waiting until it develops its own root system.
Locate an existing begonia plant and look for a healthy, disease-free stem. Examine the stem closely to see if there are tiny sprouts growing from the side of it, which are called nodes. There must be at least one sprout and two to four leaves on the stem for it to develop roots.
Cut the stem off of the plant 1/2 inch below one of the sprouts using hand pruners and making the cut straight across the stem.
Fill a small, clear, glass jar with water until it is half full. A jar like the ones that baby food comes in is ideal for propagating begonia cuttings.
Insert the cutting into the jar of water with the cut side facing downward. Look for the lowest sprout on the cutting and make sure that it is below the water line. If needed, add additional water until it is covered.
Set the jar in a location that is out of direct sunlight and wait until you see roots develop. Wait until the roots on the end of the cuttings grow to be at least 1/2-inch long.
Fill a 5- to 6-inch diameter plant pot 3/4 full of all-purpose potting soil. Stick your finger in the center to create a 2-inch deep hole that is the same width as the begonia cutting.
Insert the cutting into the hole with the roots facing downward and press the soil up against it to fill in the hole.