Broccoli 1 packet contains Broccoli - 50 seeds.This cool-season crop grows best when daytime temperatures are in the 60?F. Grow in both spring and fall, but avoid mid-summer crops as hot weather can cause premature bolting. Like spinach, can be grown in the spring or fall. In fact, you may be able to get a continual harvest throughout both seasons if you time planting correctly. A member of the cabbage family, broccoli is rich in vitamins.