Posted: 10/03/2014 at 22:23
I would say that it's worth a go sowing the calendula,nigella and cornflowers. I did an Autumn sowing of calendula and they did germinate and survived the winter in my coldframes. I've generally sown seeds indoors and them moved them out. Once they've got their true leaves showing and some good roots, they will need potting on to get the best of them.
I would definatley try and do a staggered seed sowing approach,you will be amazed at how many plants can grow from a packet if the conditions are right!