[chrisnchris]

Hi all, I have a few pots of giant begonias that are just coming into full flower, this has been their first year of planting.
I assume that the tubers are lifted & stored in a dark frost free area over winter, but when is the best time to lift them & can the tubers be split in two (or more) if big enough, how big would that be & should they be split in the autumn or just before planting.

Thanks

Chris

[mumofstig]

They can be split when really big, but tend to rot off easily when cut

The big ones they keep for shows the tubers can get up to 6inches or more across, and obviously they produce many more flowers than the small tubers we buy. So IMO it's worth keeping bigger corms, rather than splitting them up.

[sunshineband]

I agree with MoS, that it is better to keep them as large and very prolific corms.

However, if you absoutely must cut them up, wait until they have dies back completely and then make sure you have at least one bud on each. Dust the cut surface with fowers of suplphur to prevent it (hopefully prevent it) rotting.

But I have some that are four years old and give amazing displays -- corms are about 4-5 ins across 

[Goosegirl]

I love them and bought lots of plug plants from Jersey Plants - this year I mean to dig them up after the first frosts, separate them into colours, dry them off and store the corms in my shed for next year. I can't believe that about eight survived from last year over the last winter at minus 15C !!!

[chrisnchris]

However, if you absoutely must cut them up, wait until they have dies back completely and then make sure you have at least one bud on each. Dust the cut surface with fowers of suplphur to prevent it (hopefully prevent it) rotting.

Thanks, that's very useful, when you say "bud" I take it to mean to do the splitting in the spring when the corms are coming back to life.

I have 12 (I think) so I'll try a couple & see what happens.