Summarize this article in one sentence.
Schedule an approximate picking time months in advance so you get the most out of your broccoli plant. If you live in a colder climate, plant your broccoli in the spring so you can pick in the early to late summertime. In warmer climates, you have more freedom and can harvest into autumn. In general, expect to harvest broccoli about 55 to 60 days after planting. Watch the growth of the broccoli carefully and harvest them when they reach 4 to 8 inches (10 to 20cm) wide. Broccoli is a cool-season crop that harvests best in most climates during the spring or fall. Remember this in advance so you can pick during an optimum season. Floret (or flower) size is another reliable indicator that your harvest is ready. When florets at the outside edge of the broccoli head is around the size of a toothpick, your broccoli is ready for picking. Pay close attention to the plant's color when deciding whether to pick it. Your florets should be a deep green. If you see hints of yellow in the florets, your plant has begun to bloom or bolt. Harvest the broccoli immediately if it begins to turn yellow, as your plants may become overripe in several days. If your broccoli flower sprouts, it is no longer edible. Ideally, pick your broccoli the day your plant begins yellowing.

Summary:
Mark your calendar. Monitor floret and leaf growth. Check the florets for a deep green.