This year (2017) my broad bean harvest was abysmal. I don’t know what got to them, but it just did not work for me. A variety that can be planted in the Autumn here in the UK is Bunyard's exhibition. I've purchased some from Victoriana Nurseries and have been sowing them. As I live in the North East, to grow these over winter, I feel these plants would need some protection to get through so once they start to show, I cover them with a small cloche tunnel of some description.
Broad beans are part of the legume family and as I follow a 4 year crop rotation, they are to be planted where the onion and root family were the previous year. The broad beans I have sown directly are 2cm deep in double rows. The double row is (about) 23cm apart and the space between each double row is 60cm to allow me to get in and harvest the beans. A double row of these Autumn planted beans will be followed by double row in February, March then April. That should see us through. Depending on how prolific they are, these plants will hopefully be cropping well into July and August and therefore once the seeds are sown, that bed will be unusable for anything else until the plants are spent.