Contrary to popular belief your growing zone means almost nothing to your vegetable garden in North America. What?? Bear with me and by the end of this post I’m sure you’ll agree.
Just a few years ago when I really delved into gardening – spending hours poring over five-star growing guides and watching breakout channels on YouTube – I was getting inconsistent information as far as what I could grow in my garden, when I needed to start seeds and direct sow, etc. This is mostly caused by an assumption that your zone dictates when and what to do with your annual vegetables. Unfortunately, your growing zone only affects perennial plantings. By definition, in fact, a growing zone is characterized by the average low temperatures in a geographical area, dictating what perennial trees, shrubs and other plants will survive the winter and come back the following year.
Wait. Aren’t most garden variety fruits and vegetables in fact.. annuals? Yes, you’re correct! And therein lies the problem. One of the things I find most infuriating about folks who are trying to teach gardening online is that they refer to gardeners by zone, as if that broad category is important enough to even warrant mention. By titling a video “When To Start Seeds in Zone 6,” you’ve created a rift in the timing that a budding gardener like myself desperately needs to understand in order to be successful, especially in a zone like mine! While north Idaho varies greatly in growing zones (ranging from 4a to 7b) for example my area has a majority zone of 6b. Within this zone there is a variance of up to a month of growing season, meaning a huge difference in first and last frost dates within the same zone!
This is imperative to remember when planning for success in your vegetable garden: your last day of frost, in the first half of the calendar year, is when your growing season begins. Your first day of frost, in the second half of the year, is when it ends. Given that there are just a handful of perennial vegetables to be grown in most of the contiguous United States, don’t you think that’s much more pertinent to your garden planning and execution?
Frost is First
So here we’ve come to the meat and potatoes of this important lesson: ditch the concern and constant mention of zone and trade it for a focus on frost. If I had known this my first season I would have saved loads of time and energy – so much so that I made it my mission to differentiate the two so that others may learn from my mistakes.
Your frost dates are what dictate when you start your seeds, when you can plant your seedlings out into your garden beds, when your first harvest will be, and when your last harvest will be. In contrast, your growing zone only describes your average low temperatures during the winter, based off historical averages in your area. This means next to nothing to when you’re going to direct sow or start indoors – you have to count backward from your last day of frost which can be found on the Farmer’s Almanac website here – because zone doesn’t tell you when you’re going to see freezing temperatures.
So if you really want to nail down your gardening timeline visit the Farmer’s Almanac, put in your zip code and get your frost dates here. For a detailed look at what a gardener’s year should look like see my post on Grow Your Own.