Mastering the art of growing vibrant begonias at home
From the showy, tuberous varieties to the compact, fibrous-rooted types, begonias offer incredible versatility for any garden. Whether you are starting tubers indoors or tending to summer bedding, understanding their specific needs for light, water, and temperature is the secret to a lush, flowering display.
Begonias are a diverse group of tender perennials, often categorized by their root systems and growth habits. Tuberous varieties, frequently derived from Begonia × tuberhybrida, are beloved for their intense colors and extended blooming periods. These are particularly well-suited for hanging baskets and containers. In contrast, fibrous-rooted types, such as Semperflorens, are excellent for summer bedding and are among the few varieties that thrive in partial shade.
Successful cultivation begins with timing and temperature. For tuberous types, you can initiate growth in March or April by maintaining a temperature of approximately 18°C. When planting, place tubers on the surface of moist, sandy, peat-free compost with the hollow side facing up, roughly 2.5cm deep. As the plants develop leaves, they can be moved into larger 10-12.5cm pots. For more hardy varieties like Begonia grandis subsp. evansiana, which can withstand temperatures down to 0°C, tubers can be planted 5-7.5cm deep in fertile, well-drained soil.
Maintenance requires a delicate balance of moisture and nutrition. During the summer, plants in containers benefit from a high-potassium feed, such as tomato fertilizer, every two weeks from roughly six weeks after their final repotting through September. While regular watering is necessary during dry spells, it is vital to avoid wetting the foliage to prevent issues. As autumn approaches and leaves begin to yellow, prepare for overwintering. Tuberous tubers should be lifted before the first frost and stored in a frost-free shed at about 7°C in barely moist sand or soil to prevent shrivelling.
Source: How to grow begonias | Plant propagation | Gardening Australia
