When can I plant these out? Do they need to be thinned out first into their own 9cm pots?
I’d wait til this hot spell is over and then plant them straight outside - no need for the 9cm pot. They are one of the things I sow direct (no problems with mice chewing the emerging seedlings - guess they don’t like onions).
The world is a book, and those who do not travel read only one page -