As the saying goes, timing is everything—and that’s never more true than when it comes to vegetable gardening. Determining the right time to start seeds and to plant outdoors is essential, which is why following a month-by-month to-do list can mean the difference between a happy harvest and a heartbreaking one. One important note: Since the USDA Hardiness Zone Map divides North America into 11 separate zones—each zone is 10°F warmer (or colder) during an average winter than the adjacent zone—the correct start dates vary for different parts of the country. (The timeline featured here is roughly based on the timing for Zone 8.) The best way to determine the exact timing for your garden is to ask the county cooperative extension in your area for a localized calendar. (Contact info is available at extension.org.) Now, get growing!