First the Arbor Day Foundation and then the USDA came out with revised hardiness maps during the past decade, responding to our changing climate. And in both cases, the maps promise that our farm has moved to a warmer place. But can we take their recommendations as gospel?

Depending on which map you consider, our farm could have moved from zone 6a to zone 6b or even to zone 7, with average annual extreme minimums of -10 to -5, -5 to 0, and 0 to 5 respectively. However, given the data of the last two years --- with annual minimums of -12 and -22 --- we might be smarter looking for plants that can handle zone 5b or even zone 4b, suggesting that our winters have become colder rather than more mild. Granted, each zone's annual minimums are supposed to be averages only, so it's somewhat normal to exceed those minimums from time to time. Still, two years in a row of deep-freeze conditions begins to look like a trend.

I posted before about Logsdon's recommendations for easy fruit tree species by zone, with the map below summarizing the author's recommendations. If we're moving a zone or two north, though, that would mean Japanese plums, peaches, sweet cherries, and hardy figs all drop off the easy list, leaving us with only apples, pears, European plums, and sour cherries to savor. Similarly, blackberries, rabbiteye blueberries, and hardy kiwis might all become dicey if the current trend toward arctic blasts continues.

Which isn't to say that we won't be able to grow the dropped species at all. However, our sun trap along the south face of the trailer might become prime real estate for plants that have become a gamble from a climatic standpoint, and we might eventually have to admit that peaches and figs in the main part of the garden are doomed to failure.

Or maybe these brief cold spells won't have the same effect as a full zone 5 winter. Only time will tell. But I do recommend keeping track of your annual minimum temperatures and also perusing both of the new hardiness-zone maps...especially if, like Karen B., you're planning to put in $928 worth of fruit trees. If nothing else, stick to spring planting for questionable species, and plant your charges in well-drained soil shielded from wind and in an area exposed to the maximum amount of winter sun. Here's hoping all of your fruit trees --- and mine too --- are surviving this long, cold winter.