Past Articles Library | How to Grow Tuberous Begonias
What is a tuberous begonia you may ask? The answer is simple; it is a begonia that is started through a tuber, which is sort of like a bulb. But to grow these beauties takes some planning on the gardener’s side.
To begin the process, one must determine when they will need their begonias. These plants will need at least 8 weeks before they can be left outside. If you are not sure, a good overall time to start them is in March.
Planting the tuberous begonia starts with the purchasing of the tuber and soil. When purchasing the tuber, make sure to select those that are in good condition, not soft, and disease-free. As far as the soil, you will need a commercial soilless mix or a DIY version of ½ vermiculite and ½ peat moss.
Once you have the materials described above, the next step is choosing your container. The container needs to be about twice the size of the tuber and somewhat deep. After you have the container, fill it 2/3 full with the soilless mix and gently tap down on a table surface.
Next, look at your bulb. You may notice that one end of your bulb is a concave shape. This is the end by which the leaves and stems will germinate. In doing so, when you place your tuber on top of the soilless mix make sure that the concave side is up.
Once the tuber has been placed on top of the soilless mix, cover it with additional planting medium until the tuber is covered. Then, tap and gently push down the soilless mix and follow with a good watering. After that has been completed, place in a room that is kept around 60 degrees Fahrenheit along with indirect sunlight.
Keep the soil evenly moist and in about 3 weeks, one will begin to see the soil crack. This is due to the leaves and stem begin to break through the soil. In about week after the soil has cracked, you will begin to see the leaves. Continue caring for the tuberous begonia until the roots have filled up the pot. After this has happened, it is time to transplant
A 10-to 12 inch pot is a great new home for your tuberous begonia. Prior to transplanting, clean and sterilize the pot. Place drainage material in the bottom and fill ½ with a good quality potting soil. Remove the tuberous begonia from its original container, tease roots, and place in the new pot. Fill in until all the roots are covered and ½ rim of the pot is left open. This will provide space for water, which will prevent soil from running over the side of the pot. Top the soil with a slow-release fertilizer and move to a sunny location.
When the plant reaches 4 to 6 inches in height, you will need to stake the stem. This will prevent the stem from breaking off due to the weight of the leaves and flowers.
After your local frost-free date has passed, move the plant outdoors.
Tuberous begonias are a great addition to the landscape, hanging baskets and even container gardens. Just remember to bring them in before a killing frost, allow them to dry out, and then store them away until next year when the process can begin again.