By Brad Thompson
I’ve recieved many requests from begonia growers asking what to do with their tuberous begonias for the winter. I figured it would simplify things if I just gave you a page of the information.
Tuberous begonias have a winter dormant period that is determined by the day length and in cold climates, by the weather. This dormancy is a normal part of the life cycle of the tuberous begonia. Many people inquired whether they could be brought indoors and grown on through the winter. The answer is that it is possible with perfect conditions but the best course is to just let them follow their natural cycle and restart them next year. The following are the steps for storage. The time to ready your tuberous begonias for storage depends on what climate you live in so I’m going to give you both.
Northern/Cold climates: In areas that freeze during the winter, tuberous begonias must be dug up and the tubers stored indoors for the winter. The time to do this is after you’ve had that first light frost that ruins the foliage. This is a type of forced dormancy by the weather. A light frost won’t damage the tuber under the ground but a hard one will.
Southern/Warm climates: In areas that don’t have frost or rarely have frost, tuberous begonias go dormant on their own according to the day length. They usually reach that point in October or November. When they start turning yellow and dropping leaves and stems you need to stop watering.
2. What to do:
Northern/Cold climates: In cold climates, after the foliage has been ruined by the first light frost, dig up the entire plant with its tuber. Gently remove all the soil from the tuber and any loose roots. Check for pests or for rotted areas. Rotted areas can be removed with a sharp knife and dusted with a fungal powder. Lay the entire plant in a warm dry area for several days to thoroughly dry the tuber. Make sure to bring them indoors at night if it’s going to freeze. Once the tuber is dry the stem/stems should detach easily. If they don’t, it isn’t dry enough yet, wait a while longer. (don’t be overly concerned if you broke the tops off while digging or by accident, they should still be fine, it’s just better if they come off naturally because there will be less chance of rotting.)
Southern/Warm Climates: In warm areas your main worry is keeping the tubers dry during the winter. If you are growing them in the ground it will be difficult to stop them from being watered by rain so you will need to follow the directions for northern climates and dig the tubers to store them. If you are growing them in pots, however, all you need to do is put the pots where they won’t get wet or turn them on their sides so they can’t be watered.
3. How to Store:
Northern/Cold Climates: Once your tubers are thoroughly dry, place each tuber into a separate paper bag and place the bags into a cardboard box for storage. The reason for the individual bags is so that pests or disease can’t spread easily to the entire collection and because they will allow the tubers to breathe. Keep the box in a dark, dry, cool place for the winter (cool, not cold, slightly below room temp). Check the tubers periodically to make sure none are rotting and that no pests have gotten into them. Again rotted spots can be removed and the tuber redried and dusted if they aren’t too bad.
Southern/Warm Climates: Like stated above, if they are in pots they can be stored right in the pots by either tipping the pots on their sides or storing them in a cool, dry, dark area where they won’t get wet. Follow the cold area directions for tubers that are dug out of beds.
Credits / references:
Brad Thompson | Brad’s Begonia World