USDA Zone Changes - 1990 to Today
All of the Four Necessity Valve Turners, and most of the support team, tend a garden or a farm in one way or another. Whether you live in a city or on a farm, it is the season to plan for summer gardens. The biggest gamble is, when will the last frost come? And, have I started the seeds soon enough to be ready for it?
My mother taught me that her father started seeds on St. Patrick's Day. It's a good and common practice to tie earth-tending activities to holidays, holy days, moon phases, and other seasonal signs, both as a mnemonic and to entrust our gardens to the patronage of saints and angels. I start my own seeds nearly a month earlier, closer to St Valentine's Day, though on a map I'm located a full zone further north than my parent's hometown. Part of this, doubtless, is that I'm growing hardy kale and onions (neither deemed worthy of space in grandpa's carefully curated postage-stamp backyard garden) and my own willingness to risk a little bit to stretch the growing season as far as it will go. I'm hardening off kale, cabbage, nasturtiums and onions this week in Chicago, hoping weather cooperates with planting them while the moon is big in the sky next week. But another factor, which should not be overlooked, is that the USDA hardiness zones that growers rely on to plan are noticeably shifting northward.
My mom insists, year after year, that the frost free date where I am farming cannot be Mother's Day. In her mind, that is her frost free day. The reality is that zones have shifted northward a full zone for both of us - if she wanted to, she could safely put plants out as early as tax day (What a holiday! If there's a more meaningful feast that consistently falls in the teens of April, I'd be happy to re-term this).
Unfortunately, the volatility of weather (a side effect of global warming sometimes humorously referred to as global-weirding) that has accompanied climate change makes it hard for midwestern farmers to really take advantage of this shift to start production earlier. A hail storm, flood, late snowfall, or any number of other "rare" occurrences, like the tornadoes that swung through the south this week, easily kills a crop set out too soon. As US farmers, whose average income in 2018 was negative, balance the risk of crop loss against the reward, it pays for many to limit their liability and hold planting out until they are sure.
Are you planning a garden? We'd love to see your photos and hear your progress (or questions!) on facebook. One of the most healing actions we can take in this time is to be in tune with what sustains us, most directly through farms and food.