Is it too late to plant more brocolli from seed.Planted mine and they were growing well but they are opening out and not clumping together/I think the ones we used were calabrese
You can sow now for a crop late next spring.
When did you sow the others? If you sowed them this year I wouldn't be expecting a crop until next year - when you say they're 'opening out and not clumping together' what do you mean - they should just look like brassica plants at the moment.
Can we have a picture?