Whether in a pot or in a bed: begonias are frost-sensitive shade plants. If you want to overwinter begonias, you should therefore know and consider the various options.
Caring for indoor begonias over the winter
The rule of thumb for overwintering is: The warmer the room, the brighter it should be. If there is too little light, the leaves fall off. Because the begonia plants emit more CO 2 than they absorb through photosynthesis. In rooms that are too warm, plant lights prevent leaf loss during the winter.
But even in cool rooms with too much light, begonias react by shedding their leaves. Light increases the temperature on the leaf surface and activates photosynthesis. However, since fewer nutrients are transported due to the low room temperature, the plant reduces the foliage. A cold-insulating or heated mat in the root area solves the problem.
Regardless of whether the room is warm or cool: Overwintering means a vegetative rest period for begonias with a significantly lower need for water and nutrients. The rule here is: less is more. And only water so much that the root ball does not dry out completely.
Overwintering outdoor begonias safely
Begonias are not hardy. Therefore, dig out in good time before the thermometer falls below 0°C (32F). Shorten existing leaves to two centimeters (0.7 inches) and leave to rest in dry, loose plant substrate or wrapped in newspaper. The optimal winter location for begonia tubers is a frost-free room. Temperatures around 10°C (50F) are ideal.
Recommended for wintering indoor and outdoor begonias.
- Ventilate rooms regularly
- avoid direct sunlight
- do not fertilize
- moisten something
Keep dry during the winter dormant phase, otherwise, the tubers will rot! If you remove the soil completely, you must ensure that the tubers do not dry out! Because they have no protective scale leaves. Therefore, from time to time slightly moisten the tubers.
Are there hardy begonias?
These two begonia varieties are considered to be relatively hardy.
- Begonia grandis ssp evansiana
- Begonia sinensis ssp evansiana
But still, be careful. These supposedly frost-resistant begonias also need additional protection against the cold, such as a layer of brushwood.
Begonias care after the winter period
Begonia care steps from the end of February to the beginning of March: Put the open begonia bulb in the substrate and water it. Move the begonias back to a warmer and lighter spot in the house.
When the first green leaves sprout, you can start fertilizing again. But only put the begonias outdoors again after the ice saints.
Begonias bloom profusely and especially in shady locations where otherwise hardly any plants thrive. They are therefore worth saving over the winter.
If you want to save space when overwintering begonia plants, or if you know you’re watering too much, you should remove the bulbs from the soil. Be careful not to over warm your outdoor begonias. Otherwise, they will sprout too early and will wilt.