[Trebor]

Ailsa Craig is often grown as a show onion since it can get to quite a large size (1-2lb or more). Many people grow onions from sets rather than seed, I think because it is easier. You can plant out in late autumn with some varieties, but most go in late winter/ early spring. They will grow whenever you plant them, you just end up with a short growing season and so smaller onions. Given you are growing a giant onion in a short growing season then you should get a ‘small giant’ i.e. normal sized onion anyway!