I want to try some onions from seed instead of set. It seems a lot of people start them off in Jan/Feb time. Is that necessary or is it better to wait a little longer with those too?
Check the packet - some are earlier than others.
I planed to start mine on 01-Jan last year but didn't get around to it until 14-Feb. I had great Onions (first time from seed, they were much better than anything I have ever grown from sets) but I did panic towards the end as mine were showing no signs of dying down when everyone else's were ...
If memory serves me Onions are (unusually for veg) controlled by day length, so sowing late doesn't use the remainder of the Summer to ripen, once they get to the right day length they shut up show ... although not sure mine did that on time last year!!
So I think sowing-time is better not to leave-late, unlike other veg.