What is it with my Brussels Sprouts, they are all leafy for the second year?

I don’t know if it is this particular variety, or whether the soil is too rich in Nitrogen. The sprouts are all leafy for the second year now, and I am disappointed because they use to be great. I am growing the Jade variety in Zone 4. What is going on, they are very healthy plants. So, basically, they are a waste unless I want Brussels Spinach.