Developed by the University of Massachusetts, Waltham Field Station, Waltham, MA and released in 1954 and still favored by home gardeners. While the new hybrid broccoli are more efficient for farmers who do a one time harvest Waltham produces a lot of shoots and smaller heads into the cooler fall weather and can withstand frost. It is a very fine flavored broccoli produced on stocky 24 inch plants.
Heading broccoli seed can be planted directly into the garden around the last frost date (late April) or plant seeds indoors a few weeks earlier if you have a cool, sunny window and transplant to the garden. Broccoli often produces better in cool weather. A mid summer planting will avoid flea beetles if that is a problem for you, and produce in the fall.
Broccoli easily transplants when young and the plants can be placed in the ground a foot apart. Broccoli requires in a garden soil enriched with compost or organic fertilizer. After harvesting the first head with a few inches of the tender stalk, most varieties will produce side branches that can continue the production of smaller heads often into late summer or fall. During the hot summer broccoli benefits from irrigation.
Freshly harvested broccoli from the garden is just better.
You may be able to get a seed crop if you start seeds very early and transfer into the garden early. It is an annual and requires a long season of growth. Allow the head to flower and produce pods. When the pods swell with seed and begin to brown harvest them and allow them to dry. On Long Island broccoli doesn’t winter over well in the field or root cellar. Broccoli will cross with other Brassica oleraceae species in flower at the same time.