why no broccoli heads??

my calabrese plants (mr fothergills seeds, no variety named) were lovely strong plants when i put them out a couple of months ago into their specially prepared bed, loads of w r m and blood fish bone, also beaten with a spade to firm up bed, lol, (backache for me) . they went in about a foot apart and well netted. i was expecting a few dinners from them,
but most of them havent even made a head, about 4 made very small heads but only enough for one meal.  where did i go wrong, or is there still time for the others to develop?

any comments gratefully received...

the advice here
http://www.allotment-garden.org/grow-your-own/vegetables/calabrese

is that if sown at the correct time, they will produce heads in August, so if anything yours may be bolting if they are cropping already

yep out of 8 plants, 1 of mine has started to produce little heads  - oh well when i see them i nip them off and munch on them 

i wonder, should i space them out abit more (they are about 10" to 12" apart). this, as you might have guessed, is the first time ive grown this.

I'd say they are a little close together - probably more like 18-24" would have been better.  If you tried to widen the space by moving them, they may not like it, but perhaps alternate ones could be carefully moved (get as much of the root ball and soil without disturbing the roots and water in well.