Aah! My query about tuberous begonias has gone onto the Talkback section!
how much growth should I wait for before potting them up please?
What do you mean by potting up? when restarting mine I soak the tubers, plant in compost and cover till just over the tuber.
I allow them to grow to 50mm before potting up.
I wait for about 3/4 inches of growth, after having started them off in a dryish compost in a seed tray.
I have never heard of soaking them, you usually keep them fairly dry when starting off to prevent rot, but if it works for you, then thats ok.
Thank you all. They are just starting to sprout in the shallow trays, so must wait a bit longer. Thank you for the advice about water too.