How big does a begonia tuber need to be for it to grow?

Question

How big does a begonia tuber need to be for it to grow?

I have a b. Boliviensis and I took a cutting which formed a very small corm, once the corm formed the stem broke off, the corm is still hard and not mushy but it isn’t growing any bigger. The corm is about a cm and it’s in some coir/peat substrate sitting on a north-west window sill.

Answer 1

Most of begonia growers suggest a tuber be at least an inch long to provide for stem growth. But you never know! One cm might just be the perfect size to develop a few stems and a few stems are all you need!

Here are a couple of articles to help you with growing your b. Boliviensis:

https://www.gardeningknowhow.com/ornamental/flowers/begonia/growing-begonias-from-corms.htm

https://extension.umn.edu/flowers/tuberous-begonias