I've never grown broccoli, cauliflower, or Brussels sprouts before. I have no idea what they look like in sprout form. So can you send some pictures of their stages so I can learn more?
Growing Broccoli, Cauliflower, and Brussels Sprouts
Certified GKH Gardening Expert
These articles will help with growing these plants: https://www.gardeningknowhow.com/edible/vegetables/broccoli/how-to-grow-broccoli.htm