"David in Normandy" wrote
I've got a lovely yellow begonia still in flower in a pot outside at the
moment. What is the best way to overwinter it? Should I wait until the
frost kills off the top growth then dig out the corm or just put the whole
pot in a cold but frost free shed - it won't get much light though? What
is the best way of keeping the corm alive and healthy for next year?

I still have some of my mothers and she died in 1993. I just put them in the
greenhouse, stop watering completely and after all the growth has died,
clean up the soil surface and put the pot on it's side under the staging for
the winter. In the spring you will see tiny green buds on the surface of the
corm at which point you repot into fresh compost and spray lightly with
water. Over the next few weeks increase watering slowly at which point the
plants should be in full growth.
If you want to increase your plant, when the corm is big enough, you can cut
it into half or even pieces if you don't mind a lot of smaller plants.

--
Regards
Bob Hobden
just W. of London