Freezer burn

In the wacky world I live in--upstate New York during the late winter of 2016--unpredictable weather has turned my garden inside out. Weeks of temperatures hovering well above freezing encouraged tender buds to venture forth--only for their hopes of early bloom to be harshly dashed when the mercury dipped below zero! The day after my car thermometer registered a temperature of negative eleven (yes, I kid you not, check out the photo, below), I entered my garden spaces to survey the carnage. What I found astounded me. Fledgling daffodils, allium and poppy greenery valiantly pushing up through the cracked, frozen soil.  Would they survive?

Feeling that there was no time to waste, I began scouring my notebooks, kept since my training at New York's Botanical Garden. I turned to clipped magazine articles, the Internet, and questioned every friend I knew who loves gardening.  Here's what I found:

Fortunately, flowering bulbs are remarkably resilient. "Most will not be fazed by limited periods of cold weather," says Steve Zwiep, Parks Department supervisor for the city of Holland, Michigan, home of the annual Tulip Time Festival. "The risk of damage is greatest when the plants are blooming. Before the buds open, both daffodils and tulips are fairly immune to the cold, but open flowers are more sensitive to frosts and freezes."

The same thing seems to be true for my 'Stellata' magnolia tree. Even though it's covered with buds which look ready to burst forth, they have always managed to hang on without damage. Once they bloom though, it's a different story. I estimate 6 out of 10 seasons see at least a bit of flower damage on those delicate beauties. Every time it happens my heart withers right along with the frost-burned blossoms.

As for poppies and alliums, they appear to be as susceptible to unseasonable cold snaps as most other plants.  Damage above 32 °F is chilling injury rather than freeze injury. Freeze injury occurs in all plants due to ice formation. Most plants that develop in colder climates often survive with little damage if the freeze event is not too severe. Negative 11 is quite severe, but it didn't last too long.

The problem is the unseasonably warm weather BEFORE the brutally cold drop off played a dirty trick on the plants, causing them to lose their "hardening" ability (a process by which plant tissue gradually accustoms to colder temps) after the warm spell. Hardening is most probably related to an increase in solute content of the plant tissue or decreases in ice-nucleation active (INA) bacteria concentrations during cold periods, or a combination. During warm periods, plants exhibit growth, which reduces solute concentration, and INA bacteria concentration increases, which makes the plants less hardy.

So, when all is said and done, will this uniquely destructive climate damage the tender perennials? Sadly, only time will tell, but I remain hopeful that my spring garden will shine.