Overwintering begonias – frost-sensitive tubers in winter

Begonias are popular ornamental plants. They are often cultivated as annuals, although they are actually perennials. Since the tubers are not frost-resistant, begonias need to be overwintered.

Overwintering begonias is not complicated and doesn't take up much space. In return, you’ll enjoy increasingly larger plants for your garden bed and balcony. The effort is worth it!

The tubers of begonias freeze at low temperatures and die off. If they are not to be replaced every year, begonias must be overwintered. To do this, water them less starting in late September. This reduces the energy the plant spends on its leaves and allows it to store more in the tuber. Also, begonias should not bloom for too long, as this weakens their growth. Therefore, they are usually removed from the bed with a digging fork after the leaves have fallen. If early night frosts are forecast, dig up the begonias even if they still have healthy foliage.

The tubers are carefully removed from the soil before the first frost. Cut back the above-ground parts of the plant by hand-width to remove leaves and flowers. Only the tubers of the begonias are overwintered. Clean the tubers of soil to prevent rot. For the same reason, watering is unnecessary during the dormant phase. However, you should moisten the tuber slightly, as they lack protective scale leaves and are at risk of drying out. Make sure there is regular ventilation and maintain a room temperature of around 8°C. If it gets too warm, the tubers will sprout too early. Begonias overwinter very well in a sand box. Starting in February, you can pre-grow the tuber to extend the blooming period. After the ice saints, the begonia can be returned to the garden.

Even indoor begonias need a resting phase in the winter. However, due to their long blooming period, this phase differs from that of garden begonias. Indoor begonias should overwinter in a pot at a bright location. The potted begonia also needs cooler temperatures, ideally between 16 – 18°C. Simply place it in an unheated room. During the resting phase, leaf drop may occur, which can also be a sign of insufficient light. Check the location. If there is enough light, the leaf shedding does not need to be a concern. Be careful not to overwater, but make sure the root ball does not dry out completely.