Seeing as the north has a short growing season, there are handful of Brussels sprout varieties that grow best in the area. For the best results, always use transplants from the local nursery or start seeds indoors 6-8 weeks before the last scheduled frost. While the best varieties to grow in the north may be limited, the good news is, many Brussels sprouts improve with flavor after a frost.
Royal Marvel Hybrid Brussels Sprouts: Extra-early variety. Produces high yields of 1 inch sprouts dark green in color. Provides great taste as well as texture. Tastes great fresh or frozen. 85 days.