The Waltham variety of broccoli is a cold-resistant plant that produces medium to large heads. A good variety for fall planting. Waltham broccoli plants can grow up to 2 feet tall. Plant Waltham broccoli as soon as soil can be worked after the last frost. Broccoli will mature faster if planted to take advantage of cool periods later in the season. It may be planted in the fall 10-12 weeks before the first frost. The entire plant is edible, from the leaves, broccoli head, and flowers! Wonderful for soups and steaming as a side dish or served raw with a dip or hummus.