I have a small plot on my land that I plant each year and the plants all grow but I rarely get bulbs. The spot doesn't get as much sun as I would want but it should be enough to grow. Is this from not covering the seeds enough or the lack of sunlight. Everything is fine......lime,fert,moisture,timing etc. We plant acres of stuff at our camp in worse conditions the same way with fantastic results. Confusing.
Brassicas require a lot of nitrogen. Once they have started to grow broadcast Urea on them to give them a boost.
It's either seed or soil conditions. Get a soil test done. You may do the same lime/fertilizer as at camp but soil conditions could be very different.
Another factor may be your are over seeding your brassicas which will also result in not bulbing as the plants are too close together to properly grow.
This would be my guess. I had the same problem in some spots that I over seeded. Damn things are hard to see coming out of the spreader!
Yup...broadcasting of brassicas has to be light. If anything I'd rather underseed and have to do a follow up dusting after seeing them pop but honestly lot of the guys who grow the best brassica plots try for 3-6 inches between bulb plants.