Weymouth, Mass. — Nurseries and garden centers do a great job of providing started plants for the gardener in the spring, but they do nothing at all to meet his needs for the fall. So, if you want late-season cabbage, broccoli, Brussels sprouts, and so forth on your dinner plate, get ready to sow the necessary seeds now. Here in the North, June 21, or when everyone else is celebrating the first official day of summer, you should consider sowing the seeds. This will give the vegetables time to fully mature before freezing weather arrives.