[Vagabond]

I have purple sprouting broccoli grown from seed. They have been flourishing but not a single one has produced anything to harvest. This is the first time this has happened and I'm flummoxed. The seeds were from a fresh packet and the bed was prepared with well rotted manure.
The bottom leaves are now yellowing so I'm wondering if I should just call it a day and pull them up?
Was I unlucky with a packet of dud seeds or did I unwittingly do something wrong this year?
Any theories, anyone?
Thanks in advance. 

[CHRISDONOHUE]

This is quite a common problem for those who are new to growing broccoli.
Normal purple sprouting broccoli sprouts in the spring, March to April next year.   Calabrese will produce a broccoli-type crop in the same year and some varieties of broccoli, for example Summer Purple, will produce a Summer crop.

[Vagabond]

Thanks for the reply, Chris. This is my fourth year of growing psb and the past three years have cropped fine in the summer. I'll have to check the seed packet.

[Grubbypaws]

Opposite problem for me. I ordered Red Arrow which should produce sprouts in February/March. I guess I was sent the wrong plants as they are now producing, just at a time that I need more veg  (courgettes, beans, chard, beetroot, potatoes .....)