Double Tuberous Begonias, what's happening next

In answer to greenfingers question, but there have also been some other GOY members asking in comments, so i thought i would put this in a blog.
When i get a chance i will do some more. I thought i had written something here about starting them off, but i can't find it now. lol. I'm sure it's here somewhere.
Just had a powercut, when i had all but finished - had to start again. The price of electric now you would expect a better quality of service, not sudden unexpected power cuts - greed on the part of power companies, now they're owned mostly abroad!! (sorry that's not garden related, well i have electric heaters in the greenhouses)

Thank you for writing this Mark. I've never had much luck with begonias and I only have one now. I'll be looking back at this blog several times I think , so that I may keep it safely for next year.
All the best, Hywel.

Very informative blog Mark. I have a few begonias so I was happy to read your information. Thanks...

That's really helpful Mark. I try to keep my begonias going from year to year but with varied success, maybe I'll have more luck if I follow your instructions. Sometimes, when I go to get the tubers out of storage after the winter (I bury them in dry woodshavings), I've found them to be full of really tiny white wormy things and had to throw them away. Are these the vine weevil grubs you're talking about? Thanks again for the info

Thanks for everyones comments. White grubs, sounds like the Vine Weevil grubs. I always check my tubers periodicaly through the winter, if there are holes in the tuber - or if it looks like there is saw dust next to a tuber that is a sign of the evil weevil (Vine Weevil) Once they are in a tuber they will spread throughout the lot if you don't remove the tuber under attack! Sometimes it's possible to save the tuber if you catch it in time and dig out the grub with a knife, but then it's a chance as to whether there's another which would move on to another tuber. I believe they will go for any plant, but they seem to go for Begonia tubers really badly.

Mark, I was waiting for the foliage to come down but last night's frost has damaged begonias. All leaves and flowers are sadly hanging now. What should I do? Cut everything off, dug the bulbs out and store them somewhere dry?

Please help. There is plenty of information on the internet but I cannot find answers to my qiestions!

All my plants are in pots, and are now in the heated greenhouse. I've not grown them in the ground myself - But if the frost has had them i would dig them up before the frost gets them again and move them somewhere the frost won't get them. Cut off any foilage that has gone mushy (if you know what i mean) but i would leave any sound foilage as that will help feed the tuber as it goes down. keep checking and taking away any foilage - any rotting foilage will travel down the stem and rot the tuber!
Hope that will be of some help, as i say i've not grown them in the ground before.

Oh, thanks, Mark. Mine ARE in pots- and I, plonker, waited for the foliage to go down. And couldn't understand what to do with them as they were still blossoming (until frost got them last night).

If they are in pots i would leave them in the pots, but move them or you will loose them, until all the foilage has gone. Once all the leaves are gone and you're just left with the stem i lay mine on it's side then gravity helps the stem to go. If there's not much left i would tip them out of the pots and let the compost dry out. knock the compost off as it dries - trim any brown roots but stop when you get to the white ones as they are still alive and feeding the tuber. Eventually all compost gone, give the tuber a brush with a soft brush, roots trimmed, but leave any that are still white - if there are still some white roots when you start them off again they will have a head start, particuarly if there are some tap roots.
Hope your plants are ok, i think it was the first frost, so they should be. It seemed quite a hard frost here.

Thank you! I'll move them to the garage for now and wait till all the foliage goes down, then I will do what you advised after that.

Just reading through these comments - the white roots are as you cut them, the roots will all be brown on the outside. As you cut them the centre of the root will be brown and dead, or white! If you know what i mean (i'm sure you would have been aware of that anyway).