The USDA recently released its newest Plant Hardiness Zone Map, the map that gardeners use to decide when their last anticipated frost is likely to occur and when they can set out plants of various types.
The USDA reports that many areas are now half a zone warmer than on previous maps, “mostly a result of using temperature data from a longer and more recent time period.” (An interactive map is available at http://planthardiness.ars.usda.gov/PHZMWeb/). While many debate whether this reflects a global climate change or just a more accurate assessment of the data, gardeners want to know one thing: what does this mean for my 2012 garden?
Here’s what I’ll be doing differently as I move from zone 5b to zone 6a.
I’m starting seeds a few days early: While the change in zone won’t make a dramatic difference in my final frost day, I’m starting my seeds a few days early so I can harden the plants off a few days earlier in the spring.
I’ll be prepared to set plants out earlier than usual: This will be trial-and-error for a few years, I’m sure, but this year I plan to have my plants ready to set out about two weeks before I usually do. Then, I’ll monitor weather forecasts and soil temperature to decide when I can actually plant my most tender plants.
I’m growing more heat-tolerant varieties: Especially in the Midwest, it has always been a good insurance policy to select one cold-tolerant variety and one heat-tolerant variety of such temperature-sensitive plants as tomatoes and zucchini. This year, I’ve put a couple of extra heat-tolerant varieties in the mix to compensate for a potentially warmer summer.
I’m better prepared for unexpected cold snaps: A move to zone 6a certainly won’t stop a freak cold snap from coming in and harming my tender plants if it takes a mind to. I’ll be better prepared this year to respond to unexpected chill with row covers and cold frames for garden plants and sunny indoor spaces for my container garden.
I’ll be thinking of ways to extend my season on the fall end: The new zone map announcement came just as most of us are thinking of planning our gardens, but the few extra frost-free days on the spring end should be matched by a few extra on the fall end. I’ll be planning some cold-tolerant plantings for the main garden that can go in after the main crop ends to take advantage of what I hope is a long and mild fall.