Brassica Oleracea This amazing heirloom variety has been the #1 commercial brussels sprout since the 1890s until the rise of modern cultivars. It produces wonderful heavy sets of firm sprouts over an extended period of time! Beautiful compact 20-24" plants yield 50-100 or more large dark-green 1Â¼ - 1Â½" sprouts. 80-115 days from transplant. Transplant in early summer to midsummer about the same time that you would plant late, long-season cabbage. The seed should be sown in a protected location in seed flats, 4 to 5 weeks before transplanting. Transplant the seedlings to the permanent garden location when space and time allow; but at least 90 to 100 days before the first frost date for your area. Space plants 24 to 36 inches apart in the row, or 24 inches in all directions in beds. Cover seeds 1/4 to 1/2 inch deep and transplant the seedlings when they are about 3 inches tall. Do not allow transplants to become stunted in the flats before transplanting.