Fill your shady flower gardens with beautiful and energetic tuberous begonias and they will blossom continuously throughout the growing season. When you have thriving begonias, take cuttings from tuberous begonias and propagate new begonias to plant in your landscape. Begonia cuttings root easily in moist planting media and before long, you will have new begonia plants thriving and ready to plant.
Create a Forsythe pot. A Forsythe pot is a special pot that will facilitate superior rooting results with cuttings. Line the bottom of the plastic pot with paper towels to prevent the vermiculite from spilling out the drainage holes. Pour the vermiculite into the plastic pot to fill it almost completely. Insert the cork into the bottom of the clay pot to prevent water from escaping through the drainage hole. Push the clay pot down into the center of the vermiculite in the plastic pot so that just the rim protrudes from the vermiculite. Place the plastic pot into the sink and soak the vermiculite generously with water. Allow the water to drain out the holes. Fill the clay pot to the top with water. The water in the clay pot will keep the vermiculite moist.
Cut stems from the tuberous begonia. Choose stems that are approximately 3 inches long and cut them off immediately above a leaf node.
Push the stems into the moist vermiculite immediately, pushing them in at least 1 1/2 inches beneath the surface of the vermiculite. Space multiple stems approximately 3 inches apart around the perimeter of the Forsythe pot.
Place the large plastic bag around the Forsythe pot and seal the bag. Place the container in a warm location that receives indirect sunlight.
Check the clay pot inside the Forsythe pot every day or every other day and replenish the water if the water level drops in the clay pot. Do not water the vermiculite.
Look for indications of rooting beneath the vermiculite after approximately one month. When you see new growth on the stems, make a few snips in the plastic bag with a scissors to allow fresh air into the growing environment. Open the bag completely two or three days after you make the snips in the plastic to allow the cuttings to acclimate gradually to lower humidity levels.
Prepare a new growing location for the rooted cuttings. Fill new planting containers with potting soil or prepare a planting area outside.
Remove the rooted cuttings from the vermiculite carefully and plant them in the new planting locations.