What is earliest time begonia tubers can be planted in heated greenhouse? Beginning of March?
Planting Begonia Tuber
Certified GKH Gardening Expert
If you have a greenhouse you can start your tubers anytime. It can take up to 3 months for your tuber to flower.
Many gardeners start their plants 1 month before the last frost date of your growing zone.
This link will help you determine this date and your growing zone.